Substrate treatment method and substrate treatment apparatus

ABSTRACT

A substrate treatment method is provided, which includes: an organic solvent replacing step of supplying an organic solvent, whereby a liquid film of the organic solvent is formed on the substrate as covering the upper surface of the substrate to replace a rinse liquid with the organic solvent; a substrate temperature increasing step of allowing the temperature of the upper surface of the substrate to reach a first temperature level higher than the boiling point of the organic solvent after the formation of the organic solvent liquid film, whereby a vapor film of the organic solvent is formed below the entire organic solvent liquid film between the organic solvent liquid film and the substrate to levitate the organic solvent liquid film above the organic solvent vapor film; and an organic solvent removing step of removing the levitated organic solvent liquid film from above the upper surface of the substrate.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a substrate treatment method and asubstrate treatment apparatus for treating a substrate such as asemiconductor wafer.

2. Description of the Related Art

In semiconductor device production processes, a treatment liquid issupplied to a front surface of a substrate such as a semiconductor waferto treat the front surface of the substrate with the treatment liquid.

A substrate treatment apparatus of a single substrate treatment typeadapted to treat a single substrate at a time, for example, includes aspin chuck which generally horizontally holds the substrate and rotatesthe substrate, and a nozzle which supplies the treatment liquid to thefront surface of the substrate rotated by the spin chuck. For example, achemical liquid is supplied to the substrate held by the spin chuck, andthen a rinse liquid is supplied to the substrate, whereby the chemicalliquid is replaced with the rinse liquid on the substrate. Thereafter, aspin drying step is performed to remove the rinse liquid from thesubstrate. In the spin drying step, the substrate is rotated at a higherspeed to spin off the rinse liquid from the substrate (to dry thesubstrate). In the spin drying step, it is impossible to completelyremove the rinse liquid trapped in gaps of a minute pattern formed onthe front surface of the substrate, resulting in insufficient drying.

To cope with this, U.S. Pat. No. 5,882,433 proposes a method such thatan organic solvent such as liquid isopropyl alcohol (IPA) at an ordinarytemperature is supplied to the front surface of the substrate after therinsing step, whereby the rinse liquid trapped in the gaps of thepattern on the front surface of the substrate is replaced with theorganic solvent for drying the front surface of the substrate.

SUMMARY OF THE INVENTION

In the spin drying step, adjacent pattern portions of the minute patternare liable to attract each other to be brought into contact with eachother, resulting in collapse of the pattern. This is supposedly partlybecause of a surface tension of a liquid present between the adjacentpattern portions. Where an organic solvent having a lower surfacetension is supplied to the substrate before the spin drying step as inU.S. Pat. No. 5,882,433, attractive forces occurring between theadjacent pattern portions are reduced because the organic solvent whichis present between the pattern portions has a lower surface tension. Asa result, the collapse of the pattern is prevented.

In recent years, however, a minute pattern (a projection pattern, a linepattern and the like) having a higher aspect ratio is formed on a frontsurface of a semiconductor substrate for higher density integration. Theminute pattern having a higher aspect ratio is more liable to becollapsed. Therefore, it will be impossible to sufficiently suppress thecollapse of the minute pattern simply by supplying the organic solventto the front surface of the substrate before the spin drying step.

It is therefore an object of the present invention to provide asubstrate treatment method and a substrate treatment apparatus whichensure proper drying of the front surface of the substrate whilesuppressing or preventing the collapse of the pattern.

According to the present invention, there is provided a substratetreatment method, which includes: an organic solvent replacing step ofsupplying, to an upper surface of a horizontally held substrate, anorganic solvent having a lower surface tension than a rinse liquidadhering to the upper surface of the substrate, whereby a liquid film ofthe organic solvent is formed on the substrate as covering the uppersurface of the substrate to replace the rinse liquid with the organicsolvent; a substrate temperature increasing step of allowing thetemperature of the upper surface of the substrate to reach apredetermined first temperature level higher than the boiling point ofthe organic solvent after the formation of the organic solvent liquidfilm, whereby a vapor film of the organic solvent is formed below theentire organic solvent liquid film between the organic solvent liquidfilm and the upper surface of the substrate to levitate the organicsolvent liquid film above the organic solvent vapor film; and an organicsolvent removing step of removing the levitated organic solvent liquidfilm from above the upper surface of the substrate.

According to this method, the liquid organic solvent is supplied to theupper surface of the substrate to form the organic solvent liquid filmcovering the upper surface of the substrate on the substrate, wherebythe rinse liquid adhering to the upper surface of the substrate isreplaced with the liquid organic solvent. Since the organic solventliquid film covers the entire upper surface of the substrate, the rinseliquid can be properly replaced with the liquid organic solvent on theentire upper surface of the substrate. After the formation of theorganic solvent liquid film, the temperature of the upper surface of thesubstrate is allowed to reach the first temperature level. Thus, theorganic solvent vapor film is formed on the entire upper surface of thesubstrate between the organic solvent liquid film and the upper surfaceof the substrate, and the organic solvent liquid film is levitated abovethe organic solvent vapor film. In this state, the magnitude of africtional force occurring between the upper surface of the substrateand the organic solvent liquid film is generally zero, so that theorganic solvent liquid film is easily moved along the upper surface ofthe substrate.

In the organic solvent removing step, a force for moving the organicsolvent liquid film laterally of the substrate acts on the organicsolvent liquid film. Thus, the organic solvent liquid film is movedalong the upper surface of the substrate to be expelled from aperipheral portion of the substrate. The organic solvent liquid film ismoved in the form of liquid mass (i.e., without disintegration into amultiplicity of liquid droplets), whereby the organic solvent liquidfilm can be smoothly completely removed from above the substrate.

Therefore, the organic solvent does not remain in the form of liquiddroplets on the upper surface of the substrate after the removal of theorganic solvent liquid film. That is, even if a minute pattern isprovided on the upper surface of the substrate, the liquid organicsolvent does not remain in gaps of the minute pattern. Therefore, evenwhere the substrate having the minute pattern on the upper surfacethereof is treated, it is possible to properly dry the upper surface ofthe substrate while suppressing or preventing the collapse of thepattern.

According to one embodiment of the present invention, the substratetreatment method further includes a puddling step of stopping rotationof the substrate or rotating the substrate at a puddling speed in theorganic solvent replacing step.

According to this method, the puddling step is performed in the organicsolvent replacing step. In the puddling step, the rotation of thesubstrate is stopped, or the substrate is rotated at the puddling speed.As the rotation speed of the substrate is reduced, a centrifugal forceacting on the liquid organic solvent present on the substrate becomeszero or is reduced. Therefore, the liquid organic solvent is notexpelled from the peripheral portion of the substrate, but remains onthe upper surface of the substrate. As a result, the organic solventliquid film is retained in a puddle-like form on the upper surface ofthe substrate. The rinse liquid present on the upper surface of thesubstrate is replaced with the organic solvent contained in the organicsolvent liquid film retained on the upper surface of the substrate.Therefore, the rinse liquid can be more advantageously replaced with theorganic solvent on the upper surface of the substrate.

The substrate treatment method may further include a first higher speedrotation step of rotating the substrate at a first rotation speed priorto the puddling step in the organic solvent replacing step, the firstrotation speed being higher than a rotation speed of the substrateobserved in the puddling step.

According to this method, the first higher speed rotation step isperformed prior to the puddling step. In the first higher speed rotationstep, the substrate is rotated at the first rotation speed, whereby theliquid organic solvent present on the substrate receives a centrifugalforce generated by the rotation of the substrate to spread toward theperipheral portion of the substrate. This makes it possible todistribute the liquid organic solvent over the entire upper surface ofthe substrate. Therefore, the organic solvent liquid film can beretained in the puddle-like form on the upper surface of the substrateas covering the entire upper surface of the substrate in the puddlingstep to be performed subsequently to the first higher speed rotationstep. Thus, the rinse liquid present on the upper surface of thesubstrate can be properly replaced with the liquid organic solvent onthe entire upper surface of the substrate.

The substrate treatment method may further include a second higher speedrotation step of rotating the substrate at a second rotation speed afterthe puddling step in the organic solvent replacing step, the secondrotation speed being higher than a rotation speed of the substrateobserved in the puddling step.

In the puddling step, the centrifugal force acting on the liquid organicsolvent present on the substrate is zero or small and, therefore, theorganic solvent liquid film has a greater thickness. If the organicsolvent liquid film has a greater thickness when the substratetemperature increasing step is performed, the thicker organic solventliquid film should be levitated above the substrate, requiring a longerperiod for the removal of the organic solvent liquid film in the liquidfilm removing step.

According to this method, the second higher speed rotation step isperformed before the substrate temperature increasing step is startedafter the organic solvent replacing step. In the second higher speedrotation step, the substrate is rotated at the second rotation speed toreduce the thickness of the organic solvent liquid film present on thesubstrate. As a result, the organic solvent liquid film levitated abovethe substrate has a smaller thickness in the substrate temperatureincreasing step to be performed subsequently to the second higher speedrotation step. This reduces the period of the liquid film removing step.

The substrate temperature increasing step may be performed withoutrotating the substrate.

According to this method, the substrate temperature increasing step isperformed while the rotation of the substrate is stopped.

If the substrate is rotated in the substrate temperature increasingstep, the rotation speed of the peripheral portion of the substratewould be higher and, therefore, the peripheral portion would be cooled.As a result, it would be impossible to increase the temperature of theperipheral portion of the upper surface of the substrate to the desiredtemperature level (i.e., the first temperature level). In this case, itwould be impossible to properly levitate the organic solvent liquid filmabove the peripheral portion of the substrate.

In the inventive method, in contrast, the substrate temperatureincreasing step is performed without rotating the substrate, so that thetemperature of the peripheral portion of the upper surface of thesubstrate can be increased to the desired temperature level (firsttemperature level). Thus, the organic solvent liquid film can belevitated over the entire upper surface of the substrate.

The substrate treatment method may further include a substrate heatingstep of heating the substrate in the organic solvent replacing step sothat the temperature of the upper surface of the substrate becomes apredetermined second temperature level lower than the boiling point ofthe organic solvent.

According to this method, the substrate is heated in the organic solventreplacing step. That is, the upper surface of the substrate is warmed,so that the liquid organic solvent present in contact with the uppersurface of the substrate has an increased diffusion coefficient. Thisimproves the efficiency of the replacement with the organic solvent.With a higher efficiency of the replacement in the organic solventreplacing step, the period of the organic solvent replacing step isreduced.

The substrate treatment method may further include a rinsing step ofsupplying a rinse liquid to the upper surface of the substrate prior tothe organic solvent replacing step, and the substrate heating step maybe started in the rinsing step.

The first temperature level in the substrate temperature increasing stepmay be a temperature such that the organic solvent liquid film levitatedin the substrate temperature increasing step is prevented from boiling.In this case, the levitated organic solvent liquid film is substantiallyprevented from being split. Thus, the collapse of the pattern, theformation of water marks and other defects can be effectively suppressedor prevented which may otherwise occur due to the splitting of theorganic solvent liquid film after a drying step.

The first temperature level in the substrate temperature increasing stepmay be a temperature higher by 10° C. to 50° C. than the boiling pointof the organic solvent.

At least one of the first temperature level in the substrate temperatureincreasing step and the period of the substrate temperature increasingstep may be determined so that organic solvent vapor contained in theorganic solvent vapor film is prevented from breaking through theorganic solvent liquid film to above the organic solvent liquid film. Inthis case, the splitting of the levitated organic solvent liquid film iseffectively suppressed or prevented. Thus, the collapse of the pattern,the formation of water marks and other defects can be suppressed orprevented which may otherwise occur due to the splitting of the organicsolvent liquid film after the drying step.

The thickness of the organic solvent liquid film levitated in thesubstrate temperature increasing step may be determined so thatdisintegration of the organic solvent liquid film is prevented in thesubstrate temperature increasing step. According to this method, thesplitting of the levitated organic solvent liquid film is suppressed orprevented. Thus, the collapse of the pattern, the formation of watermarks and other defects can be effectively suppressed or prevented whichmay otherwise occur due to the splitting of the organic solvent liquidfilm after the drying step.

The substrate treatment method may further include an organic solventsupplying step of supplying the organic solvent to the upper surface ofthe substrate in the substrate temperature increasing step.

According to this method, the thickness of the organic solvent liquidfilm levitated above the substrate can be maintained to a desiredthickness in the organic solvent replacing step. Thus, the collapse ofthe pattern, the formation of water marks and other defects can beeffectively suppressed or prevented which may otherwise occur due to thesplitting of the organic solvent liquid film after the drying step.

According to the present invention, there is further provided asubstrate treatment apparatus which performs a rinsing step to rinse asubstrate with a rinse liquid, the apparatus including: a substrateholding unit which horizontally holds the substrate; an organic solventsupplying unit which supplies an organic solvent having a lower surfacetension than the rinse liquid to an upper surface of the substrate heldby the substrate holding unit; a heating unit which heats the substratefrom below; and a control unit which controls the organic solventsupplying unit and the heating unit to perform an organic solventreplacing step of supplying the organic solvent to the upper surface ofthe substrate whereby a liquid film of the organic solvent is formed onthe substrate as covering the upper surface of the substrate to replacethe rinse liquid with the organic solvent, a substrate temperatureincreasing step of allowing the temperature of the upper surface of thesubstrate to reach a predetermined first temperature level higher thanthe boiling point of the organic solvent after the formation of theorganic solvent liquid film, whereby a vapor film of the organic solventis formed below the entire organic solvent liquid film between theorganic solvent liquid film and the upper surface of the substrate tolevitate the organic solvent liquid film above the organic solvent vaporfilm, and an organic solvent removing step of removing the organicsolvent liquid film from above the substrate.

With this arrangement, the liquid organic solvent is supplied to theupper surface of the substrate to form the organic solvent liquid filmcovering the upper surface of the substrate on the substrate, wherebythe rinse liquid adhering to the upper surface of the substrate isreplaced with the liquid organic solvent. Since the upper surface of thesubstrate is entirely covered with the organic solvent liquid film, therinse liquid can be properly replaced with the organic solvent on theentire upper surface of the substrate. After the formation of theorganic solvent liquid film, the temperature of the upper surface of thesubstrate is allowed to reach the first temperature level. Thus, theorganic solvent vapor film is formed on the entire upper surface of thesubstrate between the organic solvent liquid film and the upper surfaceof the substrate, and the organic solvent liquid film is levitated abovethe organic solvent vapor film. In this state, the magnitude of africtional force occurring between the upper surface of the substrateand the organic solvent liquid film is generally zero, so that theorganic solvent liquid film can be easily moved along the upper surfaceof the substrate.

In the organic solvent removing step, a force for moving the organicsolvent liquid film laterally of the substrate acts on the organicsolvent liquid film. Thus, the organic solvent liquid film is movedalong the upper surface of the substrate to be expelled from aperipheral portion of the substrate. The organic solvent liquid film ismoved in the form of liquid mass (i.e., without disintegration into amultiplicity of liquid droplets), whereby the organic solvent liquidfilm can be smoothly completely removed from above the substrate.

Therefore, the organic solvent does not remain in the form of liquiddroplets on the upper surface of the substrate after the removal of theorganic solvent liquid film. That is, even if a minute pattern isprovided on the upper surface of the substrate, the liquid organicsolvent does not remain in gaps of the minute pattern. Therefore, evenwhere the substrate having the minute pattern on the upper surfacethereof is treated, it is possible to properly dry the upper surface ofthe substrate while suppressing or preventing the collapse of thepattern.

The foregoing and other objects, features and effects of the presentinvention will become more apparent from the following detaileddescription of the preferred embodiments with reference to the attacheddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view showing the construction of a substratetreatment apparatus according to one embodiment of the presentinvention.

FIG. 2 is a sectional view showing the inside of a chamber provided inthe substrate treatment apparatus shown in FIG. 1.

FIG. 3 is a plan view of a substrate holding and rotating unit and a hotplate shown in FIG. 2.

FIG. 4 is a sectional view taken along a sectional plane IV-IV in FIG.3.

FIG. 5 is an enlarged vertical sectional view of a substrate opposingsurface of the hot plate.

FIG. 6 is a sectional view schematically showing the structure of afixed pin.

FIG. 7 is a sectional view schematically showing the structures of amovable pin and a chuck opening/closing unit.

FIG. 8 is a schematic diagram showing the chuck opening/closing unitwith the movable pin kept in a clamping state.

FIG. 9 is a schematic diagram showing the chuck opening/closing unitwith the movable pin being shifted from the clamping state to anunclamping state.

FIG. 10 is a schematic diagram showing the chuck opening/closing unitwith the movable pin kept in the unclamping state.

FIG. 11 is a sectional view showing a front surface of the substrate tobe treated by a treatment unit on an enlarged scale.

FIG. 12 is a process diagram for explaining a first exemplary processfor a chemical liquid treatment to be performed by the treatment unit.

FIGS. 13A to 13I are schematic diagrams for explaining the firstexemplary process.

FIGS. 14A to 14D are schematic sectional views for explaining states ofthe upper surface of the substrate observed in the first exemplaryprocess.

FIG. 15 is a vertical sectional view of the substrate holding androtating unit and the hot plate as seen horizontally in a substratetemperature increasing step.

FIG. 16 is a vertical sectional view of the substrate holding androtating unit and the hot plate as seen horizontally in an organicsolvent removing step.

FIG. 17 is a diagram showing a change in IPA spouting flow rate and achange in substrate rotation speed in an organic solvent replacing step,the substrate temperature increasing step and the organic solventremoving step.

FIG. 18 is a schematic diagram for explaining a final rinsing step of asecond exemplary process according to the present invention.

FIG. 19 is a diagram showing a change in IPA spouting flow rate and achange in substrate rotation speed in a third exemplary processaccording to the present invention.

FIG. 20 is a diagram showing a first exemplary modification of the hotplate.

FIG. 21 is a diagram showing a second exemplary modification of the hotplate.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 is a schematic plan view showing the construction of a substratetreatment apparatus 1 according to one embodiment of the presentinvention. FIG. 2 is a vertical sectional view showing the inside of achamber 4 provided in the substrate treatment apparatus 1.

As shown in FIG. 1, the substrate treatment apparatus 1 is of a singlesubstrate treatment type adapted to treat a single disk-shaped substrateW (e.g., semiconductor wafer) at a time. The substrate treatmentapparatus 1 includes a plurality of treatment units 2 which are eachadapted to treat a substrate W with a treatment liquid or a treatmentgas, a substrate transport robot CR which loads and unloads a substrateW with respect to a chamber 4 of each of the treatment units 2, and acontroller (control unit) 3 which controls the operations of devicesprovided in the substrate treatment apparatus 1 and the opening andclosing of valves.

The treatment units 2 are of a single substrate treatment type adaptedto treat a front surface (pattern formation surface) and a back surfaceof the round substrate W with a first chemical liquid and a secondchemical liquid for chemical liquid treatments (a cleaning treatment, anetching treatment and the like). The treatment units 2 each include abox-shaped chamber 4 having an inside space, a substrate holding androtating unit (substrate holding unit) 5 which, while horizontallyholding a single substrate W in the chamber 4, rotates the substrate Wabout a vertical rotation axis A1 extending through the center of thesubstrate W, a hot plate (substrate holding unit, heating unit) 6 whichhas a substrate opposing surface 6 a for heating the substrate W frombelow and supports the substrate W from below in contact with a lowersurface of the substrate W, a hot plate attitude shifting unit 90 (seeFIG. 4) which shifts the hot plate 6 between a horizontal attitude andan inclined attitude, a treatment liquid supplying unit 7 which suppliesthe treatment liquid such as the first chemical liquid, the secondchemical liquid, a rinse liquid or the like to the substrate W held bythe substrate holding and rotating unit 5, an organic solvent supplyingunit 8 which supplies liquid IPA as an exemplary organic solvent havinga lower surface tension than the rinse liquid to the upper surface ofthe substrate W held by the substrate holding and rotating unit 5 or thehot plate 6, and a cup 9 which is capable of accommodating the substrateholding and rotating unit 5 and the hot plate 6 in a sealed state.

FIG. 3 is a plan view of the substrate holding and rotating unit 5 andthe hot plate 6. FIG. 4 is a sectional view taken along a sectionalplane IV-IV in FIG. 3.

As shown in FIGS. 2 to 4, the substrate holding and rotating unit 5includes an annular support ring 11, having a slightly greater outerdiameter than the substrate W. The support ring 11 is made of a resinmaterial having a chemical resistance, and has a rotation centerconcentric with the rotation axis A1 of the substrate W. The supportring 11 has an annular upper surface 11 a which is horizontal and flat.A plurality of fixed pins 10 (e.g., six fixed pins) immovable withrespect to the support ring 11 and a plurality of movable pins 12 (e.g.,three movable pins) which are smaller in number than the fixed pins 10and movable with respect to the support ring 11 are provided on theupper surface 11 a.

The plural fixed pins 10 are circumferentially equidistantly arranged onthe upper surface 11 a of the support ring 11. The plural movable pins12 are circumferentially arranged on the upper surface 11 a of thesupport ring 11. The movable pins 12 are provided in one-to-onecorrespondence with the same number of fixed pins 10 (e.g., three fixedpins 10) disposed adjacent to the movable pins 12. The movable pins 12are disposed adjacent to the corresponding fixed pins 10. That is, themovable pins 12 are disposed locally circumferentially of the supportring 11.

A ring rotating unit 13 for rotating the support ring 11 about therotation axis A1 is connected to the support ring 11. The ring rotatingunit 13 includes, for example, a motor, an associated transmissionmechanism and the like.

As shown in FIGS. 2 to 4, the hot plate 6 is made of, for example, aceramic material or silicon carbide (SiC), and has a disk shape. The hotplate 6 has a round flat substrate opposing surface 6 a having aslightly smaller diameter than the substrate W. The substrate opposingsurface 6 a has a diameter smaller than the inner diameter of thesupport ring 11. That is, the hot plate 6 and the support ring 11 of thesubstrate holding and rotating unit 5 do not vertically overlap witheach other. The hot plate 6 incorporates a heater 15 of, for example, aresistor type. The heater 15 is energized to generate heat to heat theentire hot plate 6 including the substrate opposing surface 6 a.

As shown in FIG. 3, a multiplicity of minute embosses 61 (e.g., 24embosses in FIG. 3) each having a generally hemispherical shape forsupporting the substrate W from below in abutment against the substrateW are distributed on the substrate opposing surface 6 a of the hot plate6. The embosses 61 are arranged at a generally uniform densitythroughout the substrate opposing surface 6 a. More specifically, fourembosses 61 are equidistantly arranged on a first phantom circle 62defined about the rotation axis A1. Eight embosses 61 are equidistantlyarranged on a second phantom circle 63 concentric with the first phantomcircle 62. Twelve embosses 61 are equidistantly arranged on a thirdphantom circle 64 concentric with the first phantom circle 62. Thesecond and third phantom circles 63, 64 respectively have diameters thatare about twice and about three times the diameter of the first phantomcircle 62. The multiple embosses 61 have substantially the samediameter.

The substrate W is spaced a minute distance (which is equivalent to aheight H to be described with reference to FIG. 5) from the substrateopposing surface 6 a above the substrate opposing surface 6 a with thelower surface thereof in abutment against the multiple embosses 61. Thesubstrate W is supported on the hot plate 6 by a frictional forceoccurring between the multiple embosses 61 and the lower surface of thesubstrate W and, when the heater 15 generates heat in this state, thesubstrate opposing surface 6 a also generates heat. The heat is appliedto the substrate W through heat transfer by heat radiation, heatconduction through a fluid present in a space defined between thesubstrate opposing surface 6 a and the substrate W, and heat conductionvia the multiple embosses 61. Thus, the substrate W supported by themultiple embosses 61 is heated.

FIG. 5 is an enlarged vertical sectional view of the substrate opposingsurface 6 a of the hot plate 6.

Balls 66 are respectively engaged in a multiplicity of small cavities 65distributively provided in the substrate opposing surface 6 a, and theembosses 61 are respectively defined by upper portions of the balls 66projecting upward from the corresponding small cavities 65. The balls 66are fixed in the small cavities 65 with an adhesive agent 67.

The balls 66 are made of, for example, a ceramic material or siliconcarbide (SiC). The multiple embosses 61 are formed as having a uniformheight, for example. The embosses 61 each have a height H (e.g., about0.1 mm) which is determined so that the substrate W supported by themultiple embosses 61 is prevented from being adsorbed on the substrateopposing surface 6 a, and a contaminant present on the substrateopposing surface 6 a is prevented from being transferred to the lowersurface of the substrate W.

Therefore, the substrate W is supported in spaced relation from thesubstrate opposing surface 6 a. Accordingly, the substrate W issubstantially prevented from being adsorbed on the substrate opposingsurface 6.a and adhering to the substrate opposing surface 6 a. Even ifa contaminant is present on the substrate opposing surface 6 a, thetransfer of the contaminant to (the lower surface of) the substrate W issuppressed or prevented.

Since the substrate W is supported by the multiple embosses 61distributed on the substrate opposing surface 6 a, the heat transferfrom the substrate opposing surface 6 a to the substrate W can be keptuniform within the plane of the substrate W. Further, this suppresses orprevents warpage of the substrate W.

The multiple embosses 61 are not necessarily required to have a uniformheight. For example, embosses 61 present on a center portion of thesubstrate opposing surface 6 a may each have a smaller height thanembosses 61 present on a peripheral portion of the substrate opposingsurface 6 a. That is, the peripheral embosses 61 may be higher than thecenter embosses 61 on the substrate opposing surface 6 a.

As shown in FIGS. 2 and 4, the hot plate 6 is supported from below by avertical plate support shaft 14 via a plurality of extension units 24(e.g., three extension units 24) and a disk-shaped or ring-shapedsupport member 17 (in FIG. 2, a disk-shaped support member 17). Thesupport member 17 has a horizontal flat support surface 17 a, and isfixed to an upper end of the plate support shaft 14. The pluralextension units (e.g., three extension units 24) are circumferentiallyequidistantly arranged on a peripheral portion of the support surface 17a of the support member 17. The three extension units 24 are disposed,for example, at the same circumferential positions as three fixed pins10 arranged every other one of the six fixed pins 10 with respect to thecircumference of the hot plate 6.

The extension units 24 are cylinders each including an extension rodextendable longitudinally thereof. The extension units 24 each have alength adjustable to a desired length within a range between a minimumlength and a maximum length by extending and contracting the extensionrod. The extension units 24 are each disposed with the length of theextension rod thereof extending vertically. The extension units 24support the peripheral portion of the hot plate 6 from below. Theextension units 24 have the same construction. Therefore, the extensionunits 24 have the same minimum length. The extension units 24 are eachconnected to an extension/contraction driving unit 25 which supplies adriving fluid for longitudinally extending and contracting the extensionrod. In this embodiment, the extension unit 24 and theextension/contraction driving unit 25 are provided as separate members,but may be provided as a unitary member such as an electromagneticactuator. In this embodiment, the hot plate attitude shifting unit 90includes the support member 17, the extension units 24 and theextension/contraction driving units 25.

All the extension units 24 are ordinarily kept in a minimum state asshown in FIG. 4 and, therefore, have the same length. Thus, the hotplate 6 is kept in the horizontal attitude. In this state, the substrateopposing surface 6 a of the hot plate 6 are kept horizontal. As will bedescribed later, the substrate W is temporarily placed on the substrateopposing surface 6 a. Even if the substrate W is placed on the substrateopposing surface 6 a, the substrate W does not move but is kept stillbecause of the frictional force of the embosses 61 as described above.

As shown in FIG. 16 to be described later, the length of one of thethree extension units 24 is kept unchanged and the lengths of the othertwo extension units 24 are increased, whereby the hot plate 6 is shiftedfrom the horizontal attitude shown in FIG. 4 to the inclined attitude.With this simple arrangement, the hot plate 6 can be shifted between thehorizontal attitude and the inclined attitude.

The plate support shaft 14 extends vertically. The plate support shaft14 is a hollow shaft, and a power supply line (not shown) for powersupply to the heater 15 and a lower pipe 18 are inserted through theinside of the plate support shaft 14.

The lower pipe 18 communicates with a lower outlet port 20 opening inthe center portion of the substrate opposing surface 6 a of the hotplate 6 through a first through-hole 55 extending thicknesswise througha center portion of the support member 17 and a second through-hole 19extending thicknesswise through the center portion of the hot plate 6.At least a part of the lower pipe 18 adjacent to the lower outlet port20 is formed of a flexible pipe. Hydrofluoric acid (an example of thefirst chemical liquid), APM (ammonia-hydrogen peroxide mixture, anexample of the second chemical liquid) and the rinse liquid areselectively supplied to the lower pipe 18 through a lower first chemicalliquid valve 21, a lower second chemical liquid valve 22 and a lowerrinse liquid valve 23. The rinse liquid is, for example, pure water(deionized water). The rinse liquid is not limited to the pure water,but may be carbonated water, electrolytic ion water, hydrogen water,ozone water or a hydrochloric acid aqueous solution having a diluteconcentration (e.g., about 10 to about 100 ppm). The first and secondchemical liquids and the rinse liquid supplied to the lower pipe 18 arespouted upward from the lower outlet port 20 through the inside of thesecond through-hole 19.

More specifically, the first chemical liquid is spouted upward from thelower outlet port 20 when the lower first chemical liquid valve 21 isopened with the lower second chemical liquid valve 22 and the lowerrinse liquid valve 23 being closed. With the substrate W being held bythe substrate holding and rotating unit 5, the first chemical liquid issupplied to a center portion of the lower surface of the substrate W.

Similarly, the second chemical liquid is spouted upward from the loweroutlet port 20 when the lower second chemical liquid valve 22 is openedwith the lower first chemical liquid valve 21 and the lower rinse liquidvalve 23 being closed. With the substrate W being held by the substrateholding and rotating unit 5, the second chemical liquid is supplied tothe center portion of the lower surface of the substrate W.

Further, the rinse liquid is spouted upward from the lower outlet port20 when the lower rinse liquid valve 23 is opened with the lower firstchemical liquid valve 21 and the lower second chemical liquid valve 22being closed. With the substrate W being held by the substrate holdingand rotating unit 5, the rinse liquid is supplied to the center portionof the lower surface of the substrate W.

Where only one lower outlet port 20 is provided as shown in FIGS. 2 to4, the outlet port is shared by the plural treatment liquids. The loweroutlet port 20 may include a plurality of outlet ports. In this case,the different outlet ports may be used for the different treatmentliquids.

A plate lift unit 16 (see FIG. 2) which moves up and down the platesupport shaft 14 is connected to the plate support shaft 14. The platelift unit 16 includes, for example, a ball screw and a motor. The platesupport shaft 14 is moved up and down by driving the plate lift unit 16,whereby the plate support shaft 14, the plural extension units 24, thesupport member 17 and the hot plate 6 are collectively moved up anddown. By the driving of the plate lift unit 16, the hot plate 6 is movedup and down between a lower position (indicated in FIG. 13A and thelike) at which the hot plate 6 is significantly spaced downward from thelower surface of the substrate W held by the substrate holding androtating unit 5 (a height position at which at least the substrateopposing surface 6 a of the hot plate 6 is located significantly belowthe lower surface of the substrate W held by the substrate holding androtating unit 5, or a height position at which the lower surface of thesubstrate W is not significantly heated by the hot plate 6 when the hotplate 6 is constantly ON) and an upper position (indicated in FIG. 13Gand the like) at which the substrate opposing surface 6 a is locatedslightly below the lower surface of the substrate W held by thesubstrate holding and rotating unit 5). As described above, the hotplate 6 and the support ring 11 of the substrate holding and rotatingunit 5 do not vertically overlap with each other and, therefore, do notinterfere with each other during the up and down movement of the hotplate 6.

As shown in FIG. 2, the treatment liquid supplying unit 7 includes afirst chemical liquid nozzle 26 which spouts the first chemical liquid,a second chemical liquid nozzle 27 which spouts the second chemicalliquid, and a rinse liquid nozzle 28 which spouts the rinse liquid. Thefirst chemical liquid nozzle 26, the second chemical liquid nozzle 27and the rinse liquid nozzle 28 are attached to a distal portion of agenerally horizontally extending arm 29 with their spouts directingdownward. The arm 29 is pivotal about a predetermined rotation axis. Thefirst chemical liquid nozzle 26, the second chemical liquid nozzle 27and the rinse liquid nozzle 28 are juxtaposed in pivoting directions inwhich the arm 29 is pivoted. An arm pivoting unit 30 which pivots thearm 29 within a predetermined angular range is connected to the arm 29.By the pivoting of the arm 29, the nozzles 26 to 28 are moved between aposition above the center portion of the substrate W supported by thesubstrate holding and rotating unit 5 or the hot plate 6 and a homeposition defined outside the cup 9.

As shown in FIG. 2, the first chemical liquid nozzle 26 is a straightnozzle which spouts hydrofluoric acid (an example of the first chemicalliquid) downward in the form of continuous stream. A first chemicalliquid line 31 serving as a first chemical liquid supply passage throughwhich the first chemical liquid is supplied from a first chemical liquidsupply source is connected to the first chemical liquid nozzle 26. Afirst chemical liquid valve 32 which opens and closes the first chemicalliquid line 31 to switch on and off the supply of the first chemicalliquid is provided in the first chemical liquid line 31. With the firstchemical liquid valve 32 being open, the first chemical liquid issupplied from the first chemical liquid line 31 to the first chemicalliquid nozzle 26. With the first chemical liquid valve 32 being closed,the supply of the first chemical liquid from the first chemical liquidline 31 to the first chemical liquid nozzle 26 is stopped.

As shown in FIG. 2, the second chemical liquid nozzle 27 is a straightnozzle which spouts APM (an example of the second chemical liquid)downward in the form of continuous stream. A second chemical liquid line33 serving as a second chemical liquid supply passage through which thesecond chemical liquid is supplied from a second chemical liquid supplysource is connected to the second chemical liquid nozzle 27. A secondchemical liquid valve 34 which opens and closes the second chemicalliquid line 33 to switch on and off the supply of the second chemicalliquid is provided in the second chemical liquid line 33. With thesecond chemical liquid valve 34 being open, the second chemical liquidis supplied from the second chemical liquid line 33 to the secondchemical liquid nozzle 27. With the second chemical liquid valve 34being closed, the supply of the second chemical liquid from the secondchemical liquid line 33 to the second chemical liquid nozzle 27 isstopped.

As shown in FIG. 2, the rinse liquid nozzle 28 is a straight nozzlewhich spouts the rinse liquid downward in the form of continuous stream.A rinse liquid line 35 serving as a rinse liquid supply passage throughwhich the rinse liquid is supplied from a rinse liquid supply source isconnected to the rinse liquid nozzle 28. A rinse liquid valve 36 whichopens and closes the rinse liquid line 35 to switch on and off thesupply of the rinse liquid is provided in the rinse liquid line 35. Withthe rinse liquid valve 36 being open, the rinse liquid is supplied fromthe rinse liquid line 35 to the rinse liquid nozzle 28. With the rinseliquid valve 36 being closed, the supply of the rinse liquid from therinse liquid line 35 to the rinse liquid nozzle 28 is stopped.

In FIG. 2, the first and second chemical nozzles 26, 27 and the rinseliquid nozzle 28 are provided on the single arm 29, but may berespectively provided on different arms.

As shown in FIG. 2, the cup 9 includes a lower cup portion 37 whichaccommodates the substrate holding and rotating unit 5 and the hot plate6, and a lid member 39 which closes an opening 38 of the lower cupportion 37. With the opening 38 of the lower cup portion 37 being closedby the lid member 39, a sealed cup having a sealed space defined thereinis provided.

The lower cup portion 37 has a generally cylindrical container-likeshape, and has a round top opening 38. The lower cup portion 37integrally includes a generally disk-shaped bottom wall 40 and aperipheral wall 41 extending upright from the bottom wall 40. Theperipheral wall 41 has a hollow cylindrical shape defined about therotation axis A1. The peripheral wall 41 has an annular upper endsurface 41 a. One of opposite ends of a waste liquid passage (not shown)is connected to an upper surface of the bottom wall 40. The other end ofthe waste liquid passage is connected to an external waste liquidfacility (not shown).

A capture cup (not shown) for capturing a treatment liquid scatteredfrom the substrate W held by the substrate holding and rotating unit 5or the hot plate 6 is provided around the peripheral wall 41. Thecapture cup is connected to the external waste liquid facility (notshown). A gap between the plate support shaft 14 and the center portionof the bottom wall 40 is sealed with an annular seal member 43.

The lid member 39 is provided in a generally horizontal attitude abovethe lower cup portion 37 with its center located on the rotation axis A1of the substrate W. A lid lift unit 54 is connected to the lid member39. The lid lift unit 54 includes, for example, a ball screw and amotor. By driving the lid lift unit 54, the lid member 39 is moved upand down between a lid closing position at which the lid member 39closes the opening 38 of the lower cup portion 37 and a lid openingposition at which the lid member 39 is retracted above the lower cupportion 37 to open the opening 38 of the lower cup portion 37. An upperannular recess 39 b having a hollow cylindrical shape coaxial with thelid member 39 is provided in a region of the lower surface of the lidmember 39 between a center portion 39 a and a peripheral portion 39 c.

The center portion 39 a of the lower surface of the lid member 39 has around horizontal flat surface. The center portion 39 a of the lowersurface of the lid member 39 is opposed to the center portion of theupper surface of the substrate W held by the substrate holding androtating unit 5 or the center portion of the upper surface of thesubstrate W held by the hot plate 6.

A seal ring 53 is provided on the peripheral portion 39 c of the lowersurface of the lid member 39 as extending along the entirecircumference. The seal ring 53 is made of, for example, an elasticresin material. With the lid member 39 located at the lid closingposition, the seal ring 53 provided on the peripheral portion 39 c ofthe lower surface of the lid member 39 abuts against the upper endsurface 41 a of the lower cup portion 37 along the entire circumferenceto seal a gap between the lid member 39 and the lower cup portion 37.

As shown in FIG. 2, an upper rinse liquid line 44, an upper organicsolvent line 45 and an upper nitrogen gas line 46 vertically extend inadjacent relation to be inserted through the center portion 39 a of thelid member 39.

A lower end of the upper rinse liquid line 44 opens in the centerportion 39 a of the lower surface of the lid member 39 to define a rinseliquid outlet port 47. An upstream end of the upper rinse liquid line 44is connected to the rinse liquid supply source. The rinse liquid issupplied to the upper rinse liquid line 44 from the rinse liquid supplysource. An upper rinse liquid valve 48 which opens and closes the upperrinse liquid line 44 to switch on and off the supply of the rinse liquidis provided in the upper rinse liquid line 44.

A lower end of the upper organic solvent line 45 opens in the centerportion 39 a of the lower surface of the lid member 39 to define anorganic solvent outlet port 49. An upstream end of the upper organicsolvent line 45 is connected to an IPA supply source. Liquid IPA issupplied to the upper organic solvent line 45 from the IPA supplysource. An organic solvent valve 50 which opens and closes the upperorganic solvent line 45 to switch on and off the supply of the liquidIPA is provided in the upper organic solvent line 45. The upper organicsolvent line 45 and the organic solvent valve 50 constitute the organicsolvent supplying unit 8.

A lower end of the upper nitrogen gas line 46 opens in the centerportion 39 a of the lower surface of the lid member 39 to define anitrogen gas outlet port 51 through which nitrogen gas (N₂) is spoutedas an exemplary inert gas. An upstream end of the upper nitrogen gasline 46 is connected to a nitrogen gas supply source. The nitrogen gasis supplied from the nitrogen gas supply source to the nitrogen gasoutlet port 51 through the upper nitrogen gas line 46 which serves as anitrogen gas supply passage. A nitrogen gas valve 52 which opens andcloses the upper nitrogen gas line 46 to switch on and off the supply ofthe nitrogen gas is provided in the upper nitrogen gas line 46.

FIG. 6 is a sectional view schematically showing the structure of thefixed pin 10. As described with reference to FIG. 3, the plural fixedpins 10 are circumferentially equidistantly arranged on the uppersurface 11 a of the support ring 11. As illustrated in FIG. 6, the fixedpins 10 each include a first lower shaft portion 71 connected to thesupport ring 11, and a first upper shaft portion 72 integrally providedon an upper end of the first lower shaft portion 71. The first lowershaft portion 71 and the first upper shaft portion 72 each have acylindrical shape. The first upper shaft portion 72 is eccentric fromthe center axis of the first lower shaft portion 71. A portion of thefirst lower shaft portion 71 connected to the first upper shaft portion72 has a tapered surface 73 having a diameter progressively increasedtoward a lower side.

FIG. 7 is a sectional view schematically showing the movable pin 12 andan arrangement around the movable pin 12. The movable pins 12 eachinclude a second lower shaft portion 74 extending vertically andconnected to the support ring 11 so as to be rotatable about a rotationaxis A2, and a second upper shaft portion 75 fixed to the second lowershaft portion 74 with its center axis being eccentric from the rotationaxis A2. The second upper shaft portion 75 has a cylindrical surface 75a to be brought into abutment against a peripheral edge of the substrateW. By the rotation of the second lower shaft portion 74, the cylindricalsurface 75 a of the second upper shaft portion 75 is shifted between anunclamping position at which the cylindrical surface 75 a is locatedaway from the rotation axis A1 (see FIG. 2) of the substrate W and aclamping position at which the cylindrical surface 75 a is locatedcloser to the rotation axis A1. The movable pins 12 each include a chuckopening/closing unit 76. The chuck opening/closing unit 76 shifts thesecond upper shaft portion 75 between the unclamping position and theclamping position to clamp and unclamp the substrate W.

As shown in FIG. 6, the peripheral edge of the substrate W abuts againstthe tapered surfaces 73 of the respective fixed pins 10 with thesubstrate W supported from below by the plural fixed pins 10. In thisstate, the second upper shaft portions 75 of the respective movable pins12 are each shifted from the unclamping position to the clampingposition shown in FIG. 7. When the second upper shaft portions 75 areeach shifted from the unclamping position to the clamping position, thecylindrical surfaces 75 a are brought into abutment against theperipheral edge of the substrate W, and press the abutting peripheraledge portions of the substrate W inward of the substrate W. Thus,peripheral edge portions of the substrate W opposite from the abuttingperipheral edge portions of the substrate W with respect to the rotationaxis A1 are brought into abutment against the first upper shaft portions72 of the fixed pins 10 located opposite from the movable pins 12 withrespect to the rotation axis A1. By thus shifting the second upper shaftportions 75 of the respective movable pins 12 from the unclampingpositions to the clamping positions, the movable pins 12 are broughtinto a clamping state. Thus, the substrate W is horizontally clamped bythe fixed pins 10 and the movable pins 12.

The cylindrical surfaces 75 a may be each formed with a V-shaped groove,which horizontally opens toward the rotation axis A1. In this case, thecylindrical surfaces 75 a are not pressed against the peripheral edge ofthe substrate W, but upper and lower tapered surfaces of the V-shapedgrooves are brought into abutment against the peripheral edge of thesubstrate W to clamp the substrate W.

FIGS. 8 to 10 are schematic diagrams showing the movement of the chuckopening/closing unit 76. FIGS. 8 to 10 are taken along a sectional planeVIII-VIII in FIG. 7. With reference to FIGS. 7 to 10, the constructionof the chuck opening/closing unit 76 will be described.

The chuck opening/closing unit 76 includes a driving permanent magnet77, a pin permanent magnet 78, an operation ring 79, an operation lever80 and a lever operating unit 81.

The driving permanent magnet 77 is fixed onto the upper surface 11 a onan outer side of the second lower shaft portion 74 of the movable pin 12present on the upper surface 11 a of the support ring 11, for example,with a magnetic pole orientation extending radially of the substrateholding and rotating unit 5. In this embodiment, more specifically, thedriving permanent magnet 77 has an N-pole located on an inner side withrespect to the rotation radius of the substrate holding and rotatingunit 5, and an S-pole located on an outer side with respect to therotation radius of the substrate holding and rotating unit 5.

The pin permanent magnet 78 has a thick annular shape or a cylindricalshape. The pin permanent magnet 78 is fitted around a middle portion ofthe second lower shaft portion 74 concentrically with the rotation axisA2 of the movable pin 12. The pin permanent magnet 78 includes anN-polarity portion 82 and an S-polarity portion 83 provided at differentcircumferential positions and respectively imparted with an N-polarityand an S-polarity. In this embodiment, the S-polarity portion 83 isoffset from the N-polarity portion 82, for example, by about 90 degreescounterclockwise about the rotation axis A2 as seen in plan.

The operation ring 79 is fitted around the second lower shaft portion 74below the pin permanent magnet 78 concentrically with the rotation axisA2 of the movable pin 12. The operation ring 79 includes a cylindricalportion 84, and a pair of projection pieces 85 sharply projectingradially outward from two different portions of the side wall of thecylindrical portion 84 offset from each other by 180 degrees. One of thepair of projection pieces 85 functions as a to-be-operated piece 86 tobe brought into abutment against the operation lever 80 for operation.Another of the pair of projection pieces 85 of the operation ring 79 islocated at the same circumferential position as the N-polarity portion82 of the pin permanent magnet 78. The operation ring 79 is rotatabletogether with the pin permanent magnet 78.

The pin permanent magnet 78 has an outer peripheral surface opposed tothe N-pole of the driving permanent magnet 77. The pin permanent magnet78 is fixed to the second lower shaft portion 74 and, therefore, aportion of the outer peripheral surface of the pin permanent magnet 78opposed to the N-pole of the driving permanent magnet 77 is changed asthe second lower shaft portion 74 is rotated.

The operation lever 80 includes, for example, a rod-shaped distalportion 80 a, and has a line shape as a whole. The operation lever 80 isslidable horizontally in a predetermined direction. As the operationlever 80 is moved, the distal portion 80 a of the operation lever 80 isrotated about the rotation axis A2. The operation lever 80 extendsradially outward of the hot plate 6 in a space below the hot plate 6while approaching the lower surface of the hot plate 6. The lowersurface of the hot plate 6 is stepped and, therefore, the operationlever 80 has a crank shape in conformity with the shape of the lowersurface of the hot plate 6 so as not to contact the hot plate 6.

The lever operating unit 81 including a cylinder and the like isconnected to the operation lever 80. By driving the lever operating unit81, the operation lever 80 is horizontally slid between a retractedposition (indicated in FIG. 8) at which the distal end 80 a is retractedlaterally of the to-be-operated piece 86 and a release position(indicated in FIG. 10) to be described later.

In FIG. 8, the movable pin 12 is illustrated as being in the clampingstate. In FIG. 9, the movable pin 12 is illustrated as being shiftedfrom the clamping state to the unclamping state. In FIG. 10, the movablepin 12 is illustrated as being in the unclamping state. In the clampingstate of the movable pin 12 shown in FIG. 8, the second upper shaftportion 75 (see FIG. 7) is located at the clamping position (indicatedin FIGS. 7 and 8). In the unclamping state of the movable pin 12 shownin FIG. 10, the second upper shaft portion 75 is located at theunclamping position (indicated in FIG. 10).

In the clamping state of the movable pin 12, as shown in FIGS. 8 to 10,the N-pole of the driving permanent magnet 77 and the S-polarity portion83 of the pin permanent magnet 78 are opposed to each other. In theunclamping state of the movable pin 12, the N-pole of the drivingpermanent magnet 77 and the N-polarity portion 82 of the pin permanentmagnet 78 are opposed to each other. The unclamping position (indicatedin FIG. 10) of the second upper shaft portion 75 (see FIG. 7) isangularly offset from the clamping position (indicated in FIGS. 7 and 8)of the second upper shaft portion 75 by about 90 degreescounterclockwise about the rotation axis A2 as seen in plan.

In the clamping state of the movable pin 12 shown in FIG. 8, asdescribed above, the N-pole of the driving permanent magnet 77 and theS-polarity portion 83 of the pin permanent magnet 78 are opposed to eachother. In this case, a portion of the pin permanent magnet 78 opposed tothe driving permanent magnet 77 has a polarity different from thepolarity of the radially inward portion of the driving permanent magnet77. Therefore, the driving permanent magnet 77 applies an attractivemagnetic force radially to the pin permanent magnet 78. In the clampingstate of the movable pin 12, therefore, the pin permanent magnet 78 ismaintained in an attitude such that the S-polarity portion 83 is opposedto the driving permanent magnet 77, whereby the second upper shaftportion 75 is maintained at the clamping position (indicated in FIGS. 7and 8). In the clamping state of the movable pin 12, the operation lever80 is retracted to the retracted position (indicated in FIG. 8) by thelever operating unit 81.

When the movable pin 12 is to be shifted from the clamping state shownin FIG. 8 to the unclamping state shown in FIG. 10, the operation lever80 is moved by the lever operating unit 81 as shown in FIG. 9 to bringthe distal portion 80 a of the operation lever 80 into abutment againstthe to-be-operated piece 86. Even after the abutment against theto-be-operated piece 86, the operation lever 80 is continuously moved bythe lever operating unit 81. The distal portion 80 a of the operationlever 80 is rotated counterclockwise about the rotation axis A2 as seenin plan, while being kept in abutment against the to-be-operated piece86. Thus, the to-be-operated piece 86 is rotated about the rotation axisA2 against the attractive magnetic force occurring between the drivingpermanent magnet 77 and the pin permanent magnet 78, whereby the secondlower shaft portion 74 and the second upper shaft portion 75 are rotatedabout the rotation axis A2 together with the to-be-operated piece 86.When the operation lever 80 is moved to the release position (indicatedin FIG. 10), the second upper shaft portion 75 (see FIG. 7) is shiftedto the unclamping position (indicated in FIG. 10), whereby the movablepin 12 is brought into the unclamping state.

In the unclamping state of the movable pin 12, as shown in FIG. 10, theN-pole of the driving permanent magnet 77 and the N-polarity portion 82of the pin permanent magnet 78 are opposed to each other as describedabove. Further, the operation lever 80 is maintained at the releaseposition by the lever operating unit 81. In this case, a portion of thepin permanent magnet 78 opposed to the driving permanent magnet 77 hasthe same polarity as the radially inward portion of the drivingpermanent magnet 77. In this state, the driving permanent magnet 77applies a repulsive magnetic force to the pin permanent magnet 78 in acircumferential direction. However, the operation lever 80 maintained atthe release position is engaged with the to-be-operated piece 86,thereby preventing the rotation of the second upper shaft portion 75 andthe to-be-operated piece 86. Therefore, the second upper shaft portion75 (see FIG. 7) is maintained at the unclamping position (indicated inFIG. 10).

When the movable pin 12 is to be shifted from the unclamping state shownin FIG. 10 to the clamping state shown in FIG. 8, the operation lever 80is moved back to the retracted position (indicated in FIG. 8) by thelever operating unit 81. With the second upper shaft 75 (see FIG. 7)being located at the unclamping position (indicated in FIG. 10), asdescribed above, the repulsive magnetic force occurs between the drivingpermanent magnet 77 and the pin permanent magnet 78. More specifically,a force is applied to the pin permanent magnet 78 clockwise as seen inplan.

Therefore, when the distal portion 80 a of the operation lever 80 andthe to-be-operated piece 86 are disengaged from each other by moving theoperation lever 80 back to the retracted position (indicated in FIG. 8),the pin permanent magnet 78 is rotated clockwise as seen in plan. Thus,the second upper shaft portion 75 (see FIG. 7) is shifted from theunclamping position (indicated in FIG. 10) to the clamping position(indicated in FIGS. 7 and 8), whereby the movable pin 12 is brought intothe clamping state.

Alternatively, the driving permanent magnet 77 may have an S-polelocated on the inner side with respect to the rotation radius, and anN-pole located on the outer side with respect to the rotation radius.

In the foregoing description, the repulsive magnetic force occursbetween the driving permanent magnet 77 and the pin permanent magnet 78when the second upper shaft portion 75 (see FIG. 7) is located at theunclamping position (indicated in FIG. 10), and the attractive magneticforce occurs between the driving permanent magnet 77 and the pinpermanent magnet 78 when the second upper shaft portion 75 is located atthe clamping position (indicated in FIGS. 7 and 8) by way of example.Alternatively, the movable pin 12 may be configured so that theattractive magnetic force occurs between the driving permanent magnet 77and the pin permanent magnet 78 when the second upper shaft portion 75is located at the unclamping position, and the repulsive magnetic forceoccurs between the driving permanent magnet 77 and the pin permanentmagnet 78 when the second upper shaft portion 75 is located at theclamping position.

The controller 3 shown in FIG. 1 includes, for example, a microcomputer.The controller 3 controls the operations of the ring rotating unit 13,the extension/contraction driving units 25, the plate lift unit 16, thearm pivoting unit 30, the lid lift unit 54, the chuck opening/closingunit 76, the lever operating unit 81 and the like according topredetermined programs. Further, the controller 3 controls electricpower to be supplied to the heater 15. In addition, the controller 3controls the opening and closing of the lower first chemical liquidvalve 21, the lower second chemical liquid valve 22, the lower rinseliquid valve 23, the first chemical liquid valve 32, the second chemicalliquid valve 34, the rinse liquid valve 36, the upper rinse liquid valve48, the organic solvent valve 50, the nitrogen gas valve 52 and thelike.

FIG. 11 is a sectional view showing the front surface of the substrate Wto be treated by the treatment unit 2 on an enlarged scale. Thesubstrate W to be treated is, for example, a silicon wafer, and includesa minute pattern 101 provided on the front surface (upper surface 100)which is a pattern formation surface. The minute pattern 101 may includeprojecting (columnar) structures 102 arranged in a matrix array as shownin FIG. 11. In this case, the structures 102 of the minute pattern 101each have a line width W1 of, for example, about 10 nm to about 45 nm,and are arranged with a gap W2 of, for example, about 10 nm to severalmicrometers.

The minute pattern 101 may include linear structures arranged in arepeated pattern defined by minute trenches.

Alternatively, the minute pattern 101 may be formed by forming aplurality of minute holes (voids or pores) in a thin film.

The minute pattern 101 includes, for example, an insulation film. Theminute pattern 101 may include an electrically conductive film. Morespecifically, the minute pattern 101 may be formed of a layered filmincluding a plurality of films stacked one on another, and may includean insulation film and an electrically conductive film. Alternatively,the minute pattern 101 may be a pattern formed of a single-layer film.The insulation film may be a silicon oxide film (SiO₂ film) or a siliconnitride film (SiN film). The electrically conductive film may be anamorphous silicon film doped with an impurity for reduction ofresistance, or may be a metal film (e.g., a metal interconnection film).

The minute pattern 101 has a thickness T of, for example, about 50 nm toabout 5 μm. The minute pattern 101 may have an aspect ratio (a ratio ofthe thickness T to the line width W1) of, for example, about 5 to about500 (typically about 5 to about 50).

FIG. 12 is a process diagram for explaining a first exemplary processfor the chemical liquid treatment to be performed by the treatment unit2. FIGS. 13A to 13I are schematic diagrams for explaining the firstexemplary process. FIGS. 14A to 14D are schematic sectional views forexplaining states of the upper surface of the substrate W observed inthe first exemplary process. FIGS. 15 and 16 are vertical sectionalviews of the substrate holding and rotating unit 5 and the hot plate 6as seen horizontally. FIG. 15 illustrates a substrate temperatureincreasing step (S10), and FIG. 16 illustrates an organic solventremoving step (S11). FIG. 17 is a diagram showing a change in IPAspouting flow rate and a change in substrate rotation speed in anorganic solvent replacing step (S9), the substrate temperatureincreasing step (S10) and the organic solvent removing step (S11).

Reference will hereinafter be made to FIGS. 1 and 2. Reference will bealso made to FIGS. 11 to 17 as required. In the following description,“the front surface (upper surface) of the substrate W” includes thefront surface (upper surface) of the substrate W itself as well as thefront surface (upper surface) of the minute pattern 101.

When the substrate treatment is to be performed by the treatment unit 2,a substrate loading step (Step S1 in FIG. 12) is performed to load anuntreated substrate W into the chamber 4. Prior to the substrate loadingstep (S1), the controller 3 turns on the heater 15 (into an energizedstate), and locates the hot plate 6 at the lower position at which thehot plate 6 is retracted downward from the substrate holding position atwhich the substrate W is held by the substrate holding and rotating unit5. Further, the controller 3 retracts all the nozzles from above thesubstrate holding and rotating unit 5. The controller 3 brings all themovable pins 12 into the unclamping state.

In the substrate loading step (S1), the controller 3 causes thesubstrate transport robot CR (see FIG. 1) to insert its hands into thechamber 4 with the substrate W held by the hands, and to transfer thesubstrate W to the substrate holding and rotating unit 5 with thepattern formation surface (front surface) facing up. The substrate Wtransferred to the substrate holding and rotating unit 5 is supported bythe plural fixed pins 10 from below. Then, the controller 3 brings theplural movable pins 12 into the clamping state. Thus, as shown in FIG.13A, the substrate W is horizontally clamped by the plural fixed pins 10(e.g., six fixed pins 10) and the plural movable pins 12 (e.g., threemovable pins 12) (in FIG. 13A, only the fixed pins 10 are shown). Thecontroller 3 causes the substrate transport robot CR to retract itshands from the chamber 4 after transferring the substrate W to thesubstrate holding and rotating unit 5.

After the substrate W is clamped by the plural fixed pins 10 and theplural movable pins 12; the controller 3 controls the ring rotating unit13 to start rotating the substrate W. The rotation speed of thesubstrate W is increased to a predetermined liquid treatment rotationspeed v3 (see FIG. 17, e.g., about 100 to about 1500 rpm) and maintainedat the liquid treatment rotation speed v3.

Although the heater 15 is turned on in the substrate loading step (S1)and, hence, the hot plate 6 is kept in the heat generating state (atthis time, the substrate opposing surface has a surface temperature of,for example, about 60° C. to about 250° C.), the heat generated by thehot plate 6 located at the lower position does not sufficiently reachthe substrate W.

In turn, a first chemical liquid step (Step S2 in FIG. 12) is performedto supply the first chemical liquid to the substrate W.

More specifically, as shown in FIG. 13B, the controller 3 controls thearm pivoting unit 30 to pivot the arm 29 from the home position to movethe first chemical liquid nozzle 26 from the retracted position to theposition above the substrate W. Thus, the first chemical liquid nozzle26 is located at the treatment position (on the rotation axis A1 of thesubstrate W above the substrate W). After the first chemical liquidnozzle 26 is located at the treatment position, the controller 3 opensthe first chemical liquid valve 32 with the second chemical liquid valve34 and the rinse liquid valve 36 being closed. Thus, the first chemicalliquid is spouted from the spout of the first chemical liquid nozzle 26.Further, the controller 3 opens the lower first chemical liquid valve 21with the lower second chemical liquid valve 22 and the lower rinseliquid valve 23 being closed. Thus, the first chemical liquid is spoutedupward from the lower outlet port 20.

The first chemical liquid supplied to the center portion of the uppersurface of the substrate W receives a centrifugal force generated by therotation of the substrate W to flow toward the peripheral portion of thesubstrate W on the upper surface of the substrate W. On the other hand,the first chemical liquid supplied to the center portion of the lowersurface of the substrate W also receives the centrifugal force generatedby the rotation of the substrate W to flow toward the peripheral portionof the substrate W on the lower surface of the substrate W. Thus, thefirst chemical liquid is supplied to the entire upper surface and theentire lower surface of the substrate W, whereby the entire upper andlower surfaces of the substrate W are treated with the first chemicalliquid. The first chemical liquid supplied to the upper and lowersurfaces of the substrate W is scattered from the peripheral portion ofthe substrate W laterally of the substrate W.

The first chemical liquid scattered from the peripheral portions of theupper and lower surfaces of the substrate W is received by an inner wallof the capture cup described above to be sent to the external wasteliquid facility (not shown) through the waste liquid passage (notshown), and treated in the waste liquid facility. The scattered liquidmay be sent to a recovery facility, rather than to the waste liquidfacility, for recycling.

After a lapse of a predetermined period from the start of the spoutingof the first chemical liquid, the controller 3 closes the first chemicalliquid valve 32 and the lower first chemical liquid valve 21 to stopspouting the first chemical liquid from the first chemical liquid nozzle26 and the lower outlet port 20.

Subsequently, a first rinsing step (Step S3 in FIG. 12) is performed toremove the first chemical liquid from the substrate W.

More specifically, as shown in FIG. 13C, the controller 3 controls thearm pivoting unit 30 to pivot the arm 29 to locate the rinse liquidnozzle 28 at the treatment position. After the rinse liquid nozzle 28 islocated at the treatment position, the controller 3 opens the rinseliquid valve 36 with the first chemical liquid valve 32 and the secondchemical liquid valve 34 being closed. Thus, the rinse liquid is spoutedfrom the spout of the rinse liquid nozzle 28. Further, the controller 3opens the lower rinse liquid valve 23 with the lower first chemicalliquid valve 21 and the lower second chemical liquid valve 22 beingclosed. Thus, the rinse liquid is spouted upward from the lower outletport 20.

The rinse liquid supplied to the center portion of the upper surface ofthe substrate W receives the centrifugal force generated by the rotationof the substrate W to flow toward the peripheral portion of thesubstrate W on the upper surface of the substrate W. On the other hand,the rinse liquid supplied to the center portion of the lower surface ofthe substrate W also receives the centrifugal force generated by therotation of the substrate W to flow toward the peripheral portion of thesubstrate W on the lower surface of the substrate W. Thus, the rinseliquid is supplied to the entire upper surface and the entire lowersurface of the substrate W to rinse away the first chemical liquid fromthe upper and lower surfaces of the substrate W. The rinse liquidsupplied to the upper and lower surfaces of the substrate W is scatteredfrom the peripheral portion of the substrate W laterally of thesubstrate W.

The rinse liquid scattered from the peripheral portions of the upper andlower surfaces of the substrate W is received by an inner wall of theperipheral wall 41 of the lower cup portion 37, and flows on the innerwall to be retained in the bottom of the lower cup portion 37. The rinseliquid retained in the bottom of the lower cup portion 37 is sent to theexternal waste liquid facility (not shown) through the waste liquidpassage (not shown), and treated in the waste liquid facility.

After a lapse of a predetermined period from the start of the spoutingof the rinse liquid, the controller 3 closes the rinse liquid valve 36and the lower rinse liquid valve 23 to stop spouting the rinse liquidfrom the rinse liquid nozzle 28 and the lower outlet port 20.

In turn, a second chemical liquid step (Step S4 in FIG. 12) is performedto supply the second chemical liquid to the substrate W.

More specifically, as shown in FIG. 13D, the controller 3 controls thearm pivoting unit 30 to pivot the arm 29 to locate the second chemicalliquid nozzle 27 at the treatment position. After the second chemicalliquid nozzle 27 is located at the treatment position, the controller 3opens the second chemical liquid valve 34 with the first chemical liquidvalve 32 and the rinse liquid valve 36 being closed. Thus, the secondchemical liquid is spouted from the spout of the second chemical liquidnozzle 27. Further, the controller 3 opens the lower second chemicalliquid valve 22 with the lower first chemical liquid valve 21 and thelower rinse liquid valve 23 being closed. Thus, the second chemicalliquid is spouted upward from the lower outlet port 20.

The second chemical liquid supplied to the center portion of the uppersurface of the substrate W receives the centrifugal force generated bythe rotation of the substrate W to flow toward the peripheral portion ofthe substrate W on the upper surface of the substrate W. On the otherhand, the second chemical liquid supplied to the center portion of thelower surface of the substrate W also receives the centrifugal forcegenerated by the rotation of the substrate W to flow toward theperipheral portion of the substrate W on the lower surface of thesubstrate W. Thus, the second chemical liquid is supplied to the entireupper surface and the entire lower surface of the substrate W, wherebythe entire upper and lower surfaces of the substrate W are treated withthe second chemical liquid. The second chemical liquid supplied to theupper and lower surfaces of the substrate W is scattered from theperipheral portion of the substrate W laterally of the substrate W.

The second chemical liquid scattered from the peripheral portions of theupper and lower surfaces of the substrate W is received by the innerwall of the peripheral wall 41 of the lower cup portion 37, and flows onthe inner wall to be retained in the bottom of the lower cup portion 37.The second chemical liquid retained in the bottom of the lower cupportion 37 is sent to the external waste liquid facility (not shown)through the waste liquid passage (not shown), and treated in the wasteliquid facility. The scattered liquid may be sent to a recoveryfacility, rather than to the waste liquid facility, for recycling.

After a lapse of a predetermined period from the start of the spoutingof the second chemical liquid, the controller 3 closes the secondchemical liquid valve 34 and the lower second chemical liquid valve 22to stop spouting the second chemical liquid from the second chemicalliquid nozzle 27 and the lower outlet port 20.

Subsequently, a second rinsing step (Step S5 in FIG. 12, see FIG. 13Cagain) is performed to remove the second chemical liquid from thesubstrate W.

More specifically, the controller 3 controls the arm pivoting unit 30 topivot the arm 29 to locate the rinse liquid nozzle 28 at the treatmentposition. After the rinse liquid nozzle 28 is located at the treatmentposition, the controller 3 opens the rinse liquid valve 36 with thefirst chemical liquid valve 32 and the second chemical liquid valve 34being closed. Thus, the rinse liquid is spouted from the spout of therinse liquid nozzle 28. Further, the controller 3 opens the lower rinseliquid valve 23 with the lower first chemical liquid valve 21 and thelower second chemical liquid valve 22 being closed. Thus, the rinseliquid is spouted upward from the lower outlet port 20.

The rinse liquid supplied to the center portion of the upper surface ofthe substrate W receives the centrifugal force generated by the rotationof the substrate W to flow toward the peripheral portion of thesubstrate W on the upper surface of the substrate W. On the other hand,the rinse liquid supplied to the center portion of the lower surface ofthe substrate W also receives the centrifugal force generated by therotation of the substrate W to flow toward the peripheral portion of thesubstrate W on the lower surface of the substrate W. Thus, the rinseliquid is supplied to the entire upper surface and the entire lowersurface of the substrate W to rinse away the second chemical liquid fromthe upper and lower surfaces of the substrate W. The rinse liquidsupplied to the upper and lower surfaces of the substrate W is scatteredfrom the peripheral portion of the substrate W laterally of thesubstrate W.

After a lapse of a predetermined period from the start of the spoutingof the rinse liquid, the controller 3 closes the rinse liquid valve 36and the lower rinse liquid valve 23 to stop spouting the rinse liquidfrom the rinse liquid nozzle 28 and the lower outlet port 20.Subsequently, the first chemical liquid step (Step S6 in FIG. 12, seeFIG. 13B again) is performed again to supply the first chemical liquidto the substrate W.

More specifically, the controller 3 controls the arm pivoting unit 30 topivot the arm 29 to locate the first chemical liquid nozzle 26 at thetreatment position. After the first chemical liquid nozzle 26 is locatedat the treatment position, the controller 3 opens the first chemicalliquid valve 32 with the second chemical liquid valve 34 and the rinseliquid valve 36 being closed. Thus, the first chemical liquid is spoutedfrom the spout of the first chemical liquid nozzle 26. Further, thecontroller 3 opens the lower first chemical liquid valve 21 with thelower second chemical liquid valve 22 and the lower rinse liquid valve23 being closed. Thus, the first chemical liquid is spouted upward fromthe lower outlet port 20.

The first chemical liquid supplied to the center portion of the uppersurface of the substrate W receives the centrifugal force generated bythe rotation of the substrate W to flow toward the peripheral portion ofthe substrate W on the upper surface of the substrate W. On the otherhand, the first chemical liquid supplied to the center portion of thelower surface of the substrate W also receives the centrifugal forcegenerated by the rotation of the substrate W to flow toward theperipheral portion of the substrate W on the lower surface of thesubstrate W. Thus, the first chemical liquid is supplied to the entireupper surface and the entire lower surface of the substrate W, wherebythe entire upper and lower surfaces of the substrate W are treated withthe first chemical liquid. The first chemical liquid supplied to theupper and lower surfaces of the substrate W is scattered from theperipheral portion of the substrate W laterally of the substrate W.

After a lapse of a predetermined period from the start of the spoutingof the first chemical liquid, the controller 3 closes the first chemicalliquid valve 32 and the lower first chemical liquid valve 21 to stopspouting the first chemical liquid from the first chemical liquid nozzle26 and the lower outlet port 20. Subsequently, a third rinsing step(Step S7 in FIG. 12, see FIG. 13C again) is performed to remove thefirst chemical liquid from the substrate W.

More specifically, the controller 3 controls the arm pivoting unit 30 topivot the arm 29 to locate the rinse liquid nozzle 28 at the treatmentposition. After the rinse liquid nozzle 28 is located at the treatmentposition, the controller 3 opens the rinse liquid valve 36 with thefirst chemical liquid valve 32 and the second chemical liquid valve 34being closed. Thus, the rinse liquid is spouted from the spout of therinse liquid nozzle 28. Further, the controller 3 opens the lower rinseliquid valve 23 with the lower first chemical liquid valve 21 and thelower second chemical liquid valve 22 being closed. Thus, the rinseliquid is spouted upward from the lower outlet port 20.

The rinse liquid supplied to the center portion of the upper surface ofthe substrate W receives the centrifugal force generated by the rotationof the substrate W to flow toward the peripheral portion of thesubstrate W on the upper surface of the substrate W. On the other hand,the rinse liquid supplied to the center portion of the lower surface ofthe substrate W also receives the centrifugal force generated by therotation of the substrate W to flow toward the peripheral portion of thesubstrate W on the lower surface of the substrate W. Thus, the rinseliquid is supplied to the entire upper surface and the entire lowersurface of the substrate W to rinse away the first chemical liquid fromthe upper and lower surfaces of the substrate W. The rinse liquidsupplied to the upper and lower surfaces of the substrate W is scatteredfrom the peripheral portion of the substrate W laterally of thesubstrate W.

After a lapse of a predetermined period from the start of the spoutingof the rinse liquid, the controller 3 closes the rinse liquid valve 36and the lower rinse liquid valve 23 to stop spouting the rinse liquidfrom the rinse liquid nozzle 28 and the lower outlet port 20, andcontrols the arm pivoting unit 30 to move the arm 29 back to its homeposition. Thus, the first chemical liquid nozzle 26, the second chemicalliquid nozzle 27 and the rinse liquid nozzle 28 are moved back to theretracted position.

Subsequently, the controller 3 controls the lid lift unit 54 to movedown the lid member 39 to the lid closing position. The opening 38 ofthe lower cup portion 37 is closed by the lid member 39 thus moved downto the lid closing position. When the lid member 39 and the lower cupportion 37 are connected to each other by a lock member (not shown) inthis state, the seal ring 53 provided on the peripheral portion 39 c ofthe lower surface of the lid member 39 abuts against the upper endsurface 41 a of the lower cup portion 37 along the entire circumference,whereby the gap between the lower cup portion 37 and the lid member 39is sealed. Thus, an inner space defined by the lower cup portion 37 andthe lid member 39 is sealed. In this state, the rinse liquid outlet port47, the organic solvent outlet port 49 and the nitrogen gas outlet port51 are opposed to the upper surface of the substrate W.

Then, a final rinsing step (Step S8 in FIG. 12) is performed on thesubstrate W.

More specifically, as shown in FIG. 13E, the controller 3 opens theupper rinse liquid valve 48 to spout the rinse liquid from the rinseliquid outlet port 47 of the upper rinse liquid line 44. The rinseliquid spouted from the rinse liquid outlet port 47 is applied to thecenter portion of the upper surface of the substrate W.

The rinse liquid supplied to the center portion of the upper surface ofthe substrate W receives the centrifugal force generated by the rotationof the substrate W to flow toward the peripheral portion of thesubstrate W on the upper surface of the substrate W. Thus, the rinseliquid is supplied to the entire upper surface of the substrate W,whereby the upper surface of the substrate W is rinsed with the rinseliquid. In the final rinsing step (S8), the rinse liquid is distributedto bottom portions of gaps of the minute pattern 101 formed on the uppersurface 100 of the substrate W (to portions of the gaps that are veryclose to the upper surface 100 of the substrate W itself) as shown inFIG. 14A.

The rinse liquid scattered from the peripheral portion of the substrateW is received by the inner wall of the peripheral wall 41 of the lowercup portion 37, and flows on the inner wall to be retained in the bottomof the lower cup portion 37. The rinse liquid retained in the bottom ofthe lower cup portion 37 is sent to the external waste liquid facility(not shown) through the waste liquid passage (not shown), and treated inthe waste liquid facility.

After a lapse of a predetermined period from the start of the spoutingof the rinse liquid, the controller 3 closes the upper rinse liquidvalve 48 to stop spouting the rinse liquid from the rinse liquid outletport 47.

Subsequently, an organic solvent replacing step (Step S9 in FIG. 12) isperformed to replace the rinse liquid with the liquid IPA on the uppersurface of the substrate W by supplying the liquid IPA to the uppersurface of the substrate W.

After the completion of the final rinsing step (S8), the controller 3accelerates the rotation of the substrate W from the liquid treatmentrotation speed v3 (see FIG. 17) to a higher rotation speed v4 (see FIG.17, e.g., 800 rpm).

When the rotation speed of the substrate W reaches the higher rotationspeed v4, as shown in FIG. 13F, the controller 3 opens the organicsolvent valve 50 to spout the liquid IPA in the form of continuousstream from the organic solvent outlet port 49 of the upper organicsolvent line 45. The IPA spouted from the organic solvent outlet port 49is in a liquid form at an ordinary temperature, i.e., has a liquidtemperature lower than the boiling point of the IPA (82.4° C.). Theliquid IPA spouted from the organic solvent outlet port 49 is applied tothe center portion of the upper surface of the substrate W. The organicsolvent replacing step (S9) is started by the start of the spouting ofthe IPA.

The liquid IPA supplied to the center portion of the upper surface ofthe substrate W receives the centrifugal force generated by the rotationof the substrate W, and flows toward the peripheral portion of thesubstrate W on the upper surface of the substrate W. Therefore, theliquid IPA supplied to the center portion of the upper surface of thesubstrate W can spread toward the peripheral portion to be therebydistributed to the entire upper surface of the substrate W. At thistime, the hot plate 6 is located at the lower position, so that the heatfrom the hot plate 6 is not sufficiently transferred to the substrate W.Therefore, the upper surface of the substrate W is maintained, forexample, at an ordinary temperature (e.g., 25° C.), so that the IPAflows on the upper surface of the substrate W while being maintained atthe ordinary temperature.

In the organic solvent replacing step (S9), the controller 3 performs ahigher speed rotation step (Step S91, see FIG. 17) to rotate thesubstrate W at the higher rotation speed v4, and then performs apuddling step (Step S92, see FIG. 17) to rotate the substrate W at apuddling speed v1 (a lower speed closer to zero in a range lower than 50rpm, e.g., about 20 rpm).

More specifically, the controller 3 rotates the substrate W at thehigher rotation speed v4 for a predetermined higher speed rotationperiod t1 (e.g., about 15 seconds) after the start of the organicsolvent replacing step (S9) (higher speed rotation step (S91)). After alapse of the higher speed rotation period t1, the controller 3 reducesthe rotation speed of the substrate W from the higher rotation speed v4to the puddling speed v1. As the rotation speed of the substrate W isreduced, the centrifugal force acting on the liquid IPA present on thesubstrate W is reduced. Therefore, the liquid IPA is not expelled fromthe peripheral portion of the substrate W but retained on the uppersurface of the substrate W. As a result, a liquid film 111 of the liquidIPA is retained in a puddle-like state on the upper surface of thesubstrate W (puddling step (S92)). Since the liquid IPA is distributedover the entire upper surface of the substrate W, the IPA liquid film111 covers the entire upper surface of the substrate W. The IPA liquidfilm 111 has a predetermined thickness (e.g., about 1 mm).

Since the IPA supplied to the upper surface of the substrate W is in aliquid form, the rinse liquid present in the gaps of the minute pattern101 can be properly replaced with the IPA as shown in FIG. 14B. The IPAliquid film 111 covers the entire upper surface of the substrate W, sothat the rinse liquid can be properly replaced with the liquid IPA onthe entire upper surface of the substrate W. After a lapse of a puddlingperiod t2 (e.g., about 15 seconds), the controller 3 controls the ringrotating unit 13 to stop the rotation of the substrate W.

In the puddling step (S92), the substrate W is rotated at the puddlingspeed v1 which is a lower rotation speed by way of example.Alternatively, the rotation of the substrate W may be stopped (therotation speed may be reduced to zero) in the puddling step (S92). Inthis case, the centrifugal force acting on the liquid IPA present on thesubstrate W becomes zero in the puddling step (S92), so that the liquidIPA is not expelled from the peripheral portion of the substrate W butretained on the upper surface of the substrate W. Thus, the puddle-likeIPA liquid film 111 is retained on the upper surface of the substrate W.

Subsequently, a substrate temperature increasing step (Step S10 in FIG.12) is performed.

More specifically, the controller 3 controls the plate lift unit 16 tomove up the hot plate 6 from the lower position to the upper position.When the hot plate 6 is moved up to the same height as the support ring11, the multiple embosses 61 on the substrate opposing surface 6 a ofthe hot plate 6 are brought into abutment against the lower surface ofthe substrate W. When the hot plate 6 is thereafter further moved up,the substrate W supported from below by the plural fixed pins 10 isdisengaged from these fixed pins 10 to be transferred to the hot plate6. The substrate W transferred to the hot plate 6 is supported frombelow by the multiple embosses 61. A state of the hot plate 6 located atthe upper position is shown in FIGS. 13G and 15.

Since the heater 15 is constantly energized, the hot plate 6 (substrateopposing surface 6 a) is kept in the heat generating state. With thesubstrate W placed on the hot plate 6, the heat from the substrateopposing surface 6 a is applied to the lower surface of the substrate Wby the heat radiation, the heat conduction through the fluid present inthe space defined between the substrate opposing surface 6 a and thesubstrate W, and the heat conduction via the multiple embosses 61. Thus,the lower surface of the substrate W is heated. The amount of the heatto be applied to the unit area of the substrate W is substantiallyuniform throughout the substrate W.

In the substrate temperature increasing step (S10), the temperature ofthe upper surface of the substrate W is increased to a predeterminedliquid film levitation temperature (first temperature) TE1 by heatingthe substrate W with the use of the hot plate 6. The liquid filmlevitation temperature TE1 is predetermined so as to be higher by 40° C.to 120° C. than the boiling point of the IPA (82.4° C.). As will bedescribed later, the IPA liquid film 111 is levitated in the substratetemperature increasing step (S10), and the liquid film levitationtemperature TE1 is a temperature such that the levitated IPA liquid film111 is prevented from boiling.

After the temperature of the upper surface of the substrate W reachesthe liquid film levitation temperature TE1, the temperature of the uppersurface of the substrate W (the temperature of the upper surface of theminute pattern 101 (see FIG. 14C and the like), more specifically, thetemperatures of the upper end surfaces 102A of the respective structures102) is maintained at the liquid film levitation temperature TE1. Theentire upper surface of the substrate W is maintained at the liquid filmlevitation temperature TE1. At this time, the amount of the heatgenerated per unit period by the heater 15 is set so that the uppersurface of the substrate W placed on the hot plate 6 is maintained atthe liquid film levitation temperature TE1 by the heating with the hotplate 6.

Shortly after the temperature of the upper surface of the substrate Wreaches the liquid film levitation temperature TE1, a part of the IPAliquid film 111 on the upper surface of the substrate W evaporates,whereby the gaps of the minute pattern 101 are, filled with theresulting IPA vapor, and an IPA vapor film 112 is formed above the uppersurface of the substrate W (above the upper end surfaces 102A of therespective structures 102). Thus, the IPA liquid film 111 is levitatedfrom the upper surface of the substrate W (from the upper end surfaces102A of the respective structures 102) (see FIG. 14C). Further, the gapsof the minute pattern 101 are filled with the IPA vapor.

When the substrate W is dried with the gaps of the minute pattern 101filled with the liquid IPA, for example, attractive forces occur betweenadjacent structures 102, so that the minute pattern 101 is liable to becollapsed. In the state shown in FIG. 14C, in contrast, the gaps of theminute pattern 101 are filled with the IPA vapor. Therefore, only a verysmall surface tension occurs between the adjacent structures 102. As aresult, the collapse of the minute pattern 101 can be suppressed orprevented which may otherwise occur due to the surface tension.

In the state shown in FIG. 14C, the IPA liquid film 111 is levitatedfrom the upper surface of the substrate W (from the upper end surfaces102A of the respective structures 102), so that the magnitude of africtional force occurring between the upper surface of the substrate Wand the IPA liquid film 111 is generally zero.

The period of the substrate temperature increasing step (S10) (a periodafter the hot plate 6 starts retaining the substrate W) is set so as tobe sufficient to levitate the IPA liquid film 111 above the entire uppersurface of the substrate W present on the hot plate 6 and to evaporatethe liquid IPA in the gaps of the minute pattern 101. In the firstexemplary process, the period of the substrate temperature increasingstep (S10) is, for example, 1 to 2 minutes.

Where the minute pattern 101 on the upper surface 100 of the substrate Whas a higher aspect ratio, the area of contact between the liquid IPAand the structures 102 of the minute pattern 101 is increased, requiringa greater heat amount for evaporating the liquid IPA in the gaps betweenthe structures 102. In order to evaporate the liquid IPA in the gapsbetween the structures 102, in this case, it is desirable to properlycontrol the liquid film levitation temperature TE1 and the substratetemperature increasing period according to the aspect ratio of theminute pattern 101 on the substrate W to be treated.

The IPA liquid film 111 levitated above the substrate W is liable to beslit or fragmented as indicated by 113 (hereinafter referred to as“slitting 113”). As the result of the slitting 113, there is aliquid-solid interface between the IPA liquid droplets and the substrateW around the slitting 113, so that the collapse of the pattern is liableto occur due to the surface tension during drying. A portion of thesubstrate W on which the slitting 113 occurs is liable to suffer from awater mark or other defects after the drying. Therefore, the slitting113 of the levitated IPA liquid film 111 should be prevented orsuppressed in the substrate temperature increasing step (S10).

The following two factors are the cause of the slitting 113 of thelevitated IPA liquid film 111.

The first causal factor is the generation of a great amount of the IPAvapor and/or the boiling of the IPA liquid film 111 due to the heatingof the substrate W for a longer period. If the IPA vapor is generated ina great amount and/or the IPA liquid film 111 boils, the IPA vapor film112 breaks through the IPA liquid film 111 to above the IPA liquid film111. As a result, the IPA liquid film 111 suffers from the slitting 113.

To cope with the first causal factor, the liquid film levitationtemperature TE1 in the substrate temperature increasing step (S10) andthe period of the substrate temperature increasing step (S10) aredetermined sous to prevent the slitting 113 in the first exemplaryprocess. In addition, the thickness of the levitated IPA liquid film 111is maintained so as to prevent the slitting during the entire period ofthe substrate temperature increasing step (S10) by continuouslysupplying the liquid IPA in the substrate temperature increasing step(S10).

The second causal factor of the slitting 113 is the splitting of the IPAliquid film 111 which is caused when the IPA liquid film 111 receivesthe centrifugal force generated by the rotation of the substrate W. Tocope with the second causal factor, the rotation of the substrate W isstopped in the substrate temperature increasing step (S10) of the firstexemplary process. This prevents the splitting of the IPA liquid filmwhich may otherwise occur due to the centrifugal force, therebypreventing the slitting 113.

After the substrate temperature increasing step (S10), an organicsolvent removing step (S11 in FIG. 12) is performed to remove the IPAliquid film 111 in the form of liquid mass above the vapor film 112.

After a lapse of a predetermined period from the transfer of thesubstrate W to the hot plate 6, more specifically, the controller 3controls the extension units 24 to shift the hot plate 6 from thehorizontal attitude to the inclined attitude as shown in FIGS. 13G and16.

The organic solvent removing step will be detailed with reference toFIG. 16. While the predetermined one 224 of the three extension units 24is kept unchanged, the other two extension units 225 (only one extensionunit 225 is shown in FIG. 16) are elongated. These two extension units225 have the same elongation amount. Thus, the hot plate 6 can beshifted to the inclined attitude. With the hot plate 6 in the inclinedattitude, the substrate opposing surface 6 a is inclined with respect tothe horizontal plane. At this time, the inclination angle is, forexample, about 1 degree. That is, the substrate opposing surface 6 a isinclined, for example, by about 1 degree with respect to the horizontalplane with the hot plate 6 kept in the inclined attitude. Thus, theupper surface of the substrate W supported by the hot plate 6 is alsoinclined, for example, by about 1 degree with respect to the horizontalplane. At this time, a circumferential portion of the hot plate 6present intermediate between the two extension units 225 is located atthe highest position, and a circumferential portion of the hot plate 6adjacent to the extension unit 224 is located at the lowest position.

With the substrate W kept in the inclined attitude, as shown in FIG. 16,the first upper shaft portion 72 and the tapered surface 73 (see FIG. 6)of one of the fixed pins 10 (fixed pin 210) located at the samecircumferential position as the shortest extension unit 224 with respectto the circumference of the hot plate 6 (closest to the shortestextension unit 224) abut against the lowest peripheral portion of theinclined substrate W, thereby preventing the substrate W from beingmoved along the substrate opposing surface 6 a.

The substrate W is supported on the hot plate 6 by the frictional forceoccurring between the multiple embosses 61 and the lower surface of thesubstrate W. With the substrate W and the hot plate 6 kept in thehorizontal attitude, the substrate W is not moved but kept still by thefrictional force. With the substrate W kept in the inclined state, onthe other hand, the weight of the substrate W acts on the substrate W.If a force acting on the substrate W along the substrate opposingsurface 6 a due to the weight of the substrate W becomes greater thanthe frictional force, there is a possibility that the substrate W ismoved along the substrate opposing surface 6 a. However, the fixed pin210 (the fixed pin 10 located at the same circumferential position asthe extension unit 224 with respect to the circumference of the hotplate 6) abuts against the lowest peripheral portion of the inclinedsubstrate W, thereby preventing the substrate W from being moved alongthe hot plate 6 to slip down from the hot plate 6. This makes itpossible to maintain both the substrate W and the hot plate 6 in theinclined attitude, while reliably preventing the substrate W fromslipping down from the hot plate 6.

Further, the slippage of the substrate W from the hotplate 6 isprevented by the fixed pin 210 which serves to support the substrate W.Therefore, the number of components and hence the costs can be reducedas compared with a case in which a slippage preventing member isprovided separately from the fixed pin 210.

At the end of the substrate temperature increasing step (S10), asdescribed above, the magnitude of the frictional force occurring betweenthe upper surface of the substrate W and the IPA liquid film 111 isgenerally zero. Therefore, the IPA liquid film 111 is easily moved alongthe upper surface of the substrate W. In the organic solvent removingstep (S11), the upper surface of the substrate W is inclined withrespect to the horizontal plane, so that the IPA liquid film 111 ismoved toward the lowest peripheral portion of the inclined substrate Walong the upper surface of the substrate W by gravity. The IPA liquidfilm 111 is moved in the form of liquid mass (i.e., withoutdisintegration into a multiplicity of liquid droplets) to be therebyremoved from above the substrate W.

After the IPA liquid film 111 is completely removed from above thesubstrate W, the controller 3 controls the extension units 24 to shiftthe hot plate 6 back into the horizontal attitude from the inclinedattitude. The controller 3 controls the plate lift unit 16 to move downthe hot plate 6 from the upper position to the lower position. Duringthe downward movement of the hot plate 6 from the upper position to thelower position, the lower surface peripheral portion of the substrate Wis brought into abutment against the tapered surfaces 73 of the fixedpins 10. Thereafter, the hot plate 6 is further moved down, whereby thesubstrate W is disengaged from the hot plate 6 to be supported frombelow by the plural fixed pins 10 of the substrate holding and rotatingunit 5. The movable pins 12 are kept in the unclamping state, so thatthe substrate W is only supported from below by the fixed pins 10 but isnot clamped by the fixed pins 10, the movable pins 12 and the like.

The controller 3 drives the lock member (not shown) to disengage the lidmember 39 and the lower cup portion 37 from each other. Then, as shownin FIG. 13I, the controller 3 controls the lid lift unit 54 to move upthe lid member 39 to the opening position.

After the hot plate 6 is moved down to the lower position, the distancebetween the hot plate 6 and the substrate W held by the substrateholding and rotating unit 5 is increased as compared with the distanceobserved when the hot plate 6 is located at the upper position.Therefore, the heat from the hot plate 6 does not sufficiently reach thesubstrate W (by the heat radiation, the heat conduction through thefluid present in the space defined between the substrate opposingsurface 6 a and the substrate W, and the heat conduction via themultiple embosses 61). Thus, the heating of the substrate W by the hotplate 6 ends, whereby the temperature of the substrate W is reducedsubstantially to the ordinary temperature.

In this manner, the chemical liquid treatment of the single substrate Wis completed, and the substrate transfer robot CR (see FIG. 1) unloadsthe treated substrate W from the chamber 4 (Step S12 in FIG. 12).

As described above, the rinse liquid present in the gaps of the minutepattern 101 is replaced with the liquid IPA by supplying the liquid IPAto the upper surface of the substrate to form the IPA liquid film 111covering the upper surface of the substrate W. Since the entire uppersurface of the substrate W is covered with the IPA liquid film 111, therinse liquid present in the gaps of the minute pattern 101 can beproperly replaced with the liquid IPA on the entire upper surface of thesubstrate W. After the formation of the IPA liquid film 111, thetemperature of the upper surface of the substrate W is allowed to reach(increased to) the liquid film levitation temperature TE1. Thus, the IPAvapor film 112 is formed between the IPA liquid film 111 and the uppersurface of the substrate W over the entire upper surface of thesubstrate W and, at the same time, the IPA liquid film 111 is levitatedabove the IPA vapor film 112. In this state, the magnitude of thefrictional force occurring between the upper surface of the substrate Wand the IPA liquid film 111 is generally zero. Therefore, the IPA liquidfilm 111 is easily moved along the upper surface of the substrate W.

In the organic solvent removing step (S11), the upper surface of thesubstrate W is inclined with respect to the horizontal plane by shiftingthe substrate W and the hot plate 6 into the inclined attitude whilemaintaining the substrate W and the hot plate 6 in a predeterminedattitude relationship. Thus, the levitated IPA liquid film 111 is movedalong the upper surface of the substrate W toward the lowest peripheralportion of the inclined substrate W by gravity to be thereby removedfrom the peripheral portion of the substrate W. The IPA liquid film 111is moved in the form of liquid mass (without disintegration into amultiplicity of liquid droplets) to be thereby smoothly and completelyremoved from above the substrate W.

Therefore, no IPA liquid droplets remain on the upper surface of thesubstrate W after the removal of the IPA liquid film 111. That is, evenif the minute pattern 101 is provided on the upper surface of thesubstrate W, the liquid IPA does not remain in the gaps of the minutepattern 101. Therefore, even where the substrate W having the minutepattern 101 on the upper surface thereof is treated, it is possible toproperly dry the upper surface of the substrate W while suppressing orpreventing the collapse of the pattern.

In the organic solvent replacing step (S9), the substrate W is rotatedat the puddling speed v1. As the rotation speed of the substrate W isthus reduced, the centrifugal force acting on the liquid IPA on thesubstrate W becomes zero or is reduced. Therefore, the liquid IPA is notexpelled from the peripheral portion of the substrate W but is retainedon the upper surface of the substrate W. As a result, the puddle-likeIPA liquid film 111 is retained on the upper surface of the substrate W.The rinse liquid present on the upper surface of the substrate W isreplaced with the IPA contained in the IPA liquid film 111 retained onthe upper surface of the substrate W. Thus, the replacement of the rinseliquid with the IPA on the upper surface of the substrate W can be moreadvantageously achieved.

The first higher speed rotation step (S91) is performed prior to thepuddling step (S92). In the first higher speed rotation step (S91), thesubstrate W is rotated at the first rotation speed, whereby the liquidIPA present on the substrate W receives the centrifugal force generatedby the rotation of the substrate W to spread toward the peripheralportion of the substrate. Thus, the liquid IPA can be distributed overthe entire upper surface of the substrate W. In the puddling step (S92)subsequent to the first higher speed rotation step (S91), therefore, thepuddle-like IPA liquid film 111 covering the entire upper surface of thesubstrate W can be retained on the upper surface of the substrate W.Thus, the rinse liquid present on the upper surface of the substrate Wcan be properly replaced with the liquid IPA on the entire upper surfaceof the substrate W.

The substrate temperature increasing step (S10) is performed with therotation of the substrate W stopped. If the substrate W is rotated inthe substrate temperature increasing step (S8), the rotation speed ofthe peripheral portion of the substrate W would be higher and,therefore, the peripheral portion would be cooled. As a result, it wouldbe impossible to increase the temperature of the peripheral portion ofthe upper surface of the substrate W to the liquid film levitationtemperature TE1. In this case, it would be impossible to properlylevitate the IPA liquid film 111 above the peripheral portion of thesubstrate W.

In the first exemplary process, in contrast, the rotation of thesubstrate W is stopped when the substrate temperature increasing step(S10) is performed, so that the temperature of the peripheral portion ofthe upper surface of the substrate W can be increased to the liquid filmlevitation temperature TE1. Thus, the IPA liquid film 111 can belevitated over the entire upper surface of the substrate W.

The hot plate 6 supports the substrate W from below in contact with thesubstrate W while heating the substrate W from below. The hot plate 6 isshifted from the horizontal attitude to the inclined attitude, wherebythe upper surface of the substrate W is inclined with respect to thehorizontal plane with the substrate W properly retained on the hot plate6. This makes it possible to incline the upper surface of the substrateW with respect to the horizontal plane while heating the substrate Wwith the hot plate 6.

The peripheral portion of the hot plate 6 is supported from below by theplural extension units 24. The plural extension units 24 are controlledas having the same length, whereby the hot plate 6 is maintained in thehorizontal attitude. Further, at least one of the extension units 24 isallowed to have a length different from those of the other extensionunits 24, whereby the hot plate 6 is maintained in the inclinedattitude. With this simple arrangement, the hot plate 6 can be shiftedbetween the horizontal attitude and the inclined attitude.

FIG. 18 is a schematic diagram for explaining a final rinsing step (S8)of a second exemplary process according to the present invention.

The second exemplary process to be performed by the substrate treatmentapparatus 1 differs from the first exemplary process described above inthat the upper surface of the substrate W is warmed by the hot plate 6in the final rinsing step (S8) and the organic solvent replacing step(S9). The second exemplary process has the same process flow as thefirst exemplary process shown in FIG. 12.

In this case, the controller 3 controls the plate lift unit 16 to moveup the hot plate 6 from the lower position (indicated in FIG. 13A andthe like) to an intermediate position (indicated in FIG. 18, a heightposition at which at least the substrate opposing surface 6 a of the hotplate 6 is located below the lower surface of the substrate W held bythe substrate holding and rotating unit 5) prior to the final rinsingstep (S8) or in the final rinsing step (S8). Therefore, the hot plate 6is located at the intermediate position during the final rinsing step(S8) and the organic solvent replacing step (S9).

When the heater 15 is energized in the heat generating state with thehot plate 6 being located at the intermediate position, the heat fromthe substrate opposing surface 6 a is applied to the substrate W held bythe substrate holding and rotating unit 5 by the heat radiation. In thisstate, the hot plate 6 and the substrate W are spaced from each other,so that a smaller amount of heat is applied to the substrate W than whenthe substrate W is placed on the hot plate 6.

In the final rinsing step (S8) of the second exemplary process, thetemperature of the upper surface of the substrate W is increased up to apredetermined preheating temperature (second temperature) TE2 by heatingthe substrate W with the hot plate 6. The preheating temperature TE2 isa temperature (e.g., about 40° C. to about 80° C.) predetermined so asto be lower than the boiling point of IPA (82.4° C.) and higher than anordinary temperature.

After the temperature of the upper surface of the substrate W reachesthe preheating temperature TE2, the temperature of the upper surface ofthe substrate W (the temperature of the upper surface of the minutepattern 101 (see FIG. 14C and the like), more specifically, the upperend surfaces 102A of the respective structures 102) is maintained at thepreheating temperature TE2. At this time, the entire upper surface ofthe substrate W is maintained at the preheating temperature TE2. Thatis, the height of the intermediate position of the hot plate 6 isdetermined so that the upper surface of the substrate W can bemaintained at the preheating temperature TE2.

In the final rinsing step (S8) and the organic solvent replacing step(S9) of the second exemplary process, the upper surface of the substrateW is warmed to the preheating temperature TE2. Therefore, the liquid IPAkept in contact with the upper surface of the substrate W has anincreased diffusion coefficient. This improves the efficiency of thereplacement with the IPA. As a result, the period of the organic solventreplacing step (S9) can be reduced.

Since the substrate temperature increasing step (S10) is started withthe upper surface of the substrate W warmed, it is possible to reducethe time required for increasing the temperature of the upper surface ofthe substrate W up to the liquid film levitation temperature TE1. As aresult, the period of the substrate temperature increasing step (S10)can be reduced.

After the end of the period of the organic solvent replacing step (S9),the controller 3 controls the plate lift unit 16 to move up the hotplate 6 from the intermediate position (indicated in FIG. 18) to theupper position (indicated in FIG. 13G and the like). Thus, the substrateW is disengaged from the substrate holding and rotating unit 5 to betransferred to the hot plate 6. Then, the substrate temperatureincreasing step (S10) is performed.

In the second exemplary process, the heating of the substrate W with thehot plate 6 is started in the final rinsing step (S8), but may bestarted in the organic solvent replacing step (S9).

FIG. 19 is a diagram showing a change in IPA spouting flow rate and achange in substrate rotation speed in a third exemplary processaccording to the present invention.

The third exemplary process to be performed by the substrate treatmentapparatus 1 differs from the first exemplary process described above inthat a film thickness reducing step (Step S93, see FIG. 19) is performedbefore the substrate temperature increasing step (S10) after thepuddling step (S92) in the organic solvent replacing step (S9). In thefilm thickness reducing step (S93), the substrate W is rotated at atreatment rotation speed v2 (film thickness reducing rotation speed)that is higher than a rotation speed v1 of the substrate W observed inthe puddling step (S92) and lower than the liquid treatment rotationspeed v3. In synchronism with the start of the film thickness reducingstep (S93), the spouting of the IPA is stopped.

After the completion of the puddling step (S92), more specifically, thecontroller 3 accelerates the rotation of the substrate W from thepuddling speed v1 to the film thickness reducing rotation speed v2 (thatis not lower than the puddling speed v1 and lower than the liquidtreatment rotation speed v3, e.g., not lower than 50 rpm and lower than100 rpm), and rotates the substrate W at the film thickness reducingrotation speed v2 for a predetermined film thickness reducing period t3(e.g., for about 5 seconds). In synchronism with the start of therotation in the film thickness reducing step (S93), the spouting of theIPA is stopped. By the lower speed rotation of the substrate W withoutthe supply of the IPA, a centrifugal force generated by the rotation ofthe substrate W acts on the IEA liquid film 111 present on the substrateW to spread the IPA liquid film 111, thereby reducing the thickness ofthe IPA liquid film 111 (e.g., to 0.5 mm).

In the puddling step (S92), the centrifugal force acting on the liquidIPA present on the substrate W is zero or small and, therefore, the IPAliquid film 111 has a greater thickness (e.g., 1 mm). If the IPA liquidfilm 111 has a greater thickness when the substrate temperatureincreasing step (S10) is performed, the IPA liquid film 111 levitatedabove the substrate W also has a greater thickness, requiring a longerperiod for removing the IPA liquid film 111 in the liquid film removingstep (S11).

In the third exemplary process, in contrast, the film thickness reducingstep (S93) is performed prior to the substrate temperature increasingstep (S10), so that the IPA liquid film 111 levitated above thesubstrate W has a smaller thickness (e.g., 0.5 mm) in the substratetemperature increasing step (S10). Thus, the period of the liquid filmremoving step (S11) (the time required for removing the IPA liquid film111) can be reduced.

In the first to third exemplary processes, the final rinsing step (S8)is performed while sealing the inner space defined by the lower cupportion 37 and the lid member 39 by way of example. Alternatively, thefinal rinsing step (S8) may be performed while opening the inner spacedefined by the lower cup portion 37 and the lid member 39 (with the lidmember 39 being located at the opening position). The rinse liquid fromthe rinse liquid outlet port 47 of the upper rinse liquid line 44 may besupplied to the upper surface of the substrate W, or the rinse liquidfrom the rinse liquid nozzle 28 may be supplied to the upper surface ofthe substrate W with the rinse liquid nozzle 28 being opposed to theupper surface of the substrate W. In this case, the inner space definedby the lower cup portion 37 and the lid member 39 is sealed after thefinal rinsing step (S8).

In the first to third exemplary processes, the first chemical liquidstep (S2, S6) is repeated a plurality of times (twice) by way ofexample, but may be performed once.

In the first and second chemical liquid steps (S2, S4, S6) and the firstto third rinsing steps (S3, S5, S7) of the first to third exemplaryprocesses, both the upper and lower surfaces of the substrate W aretreated by way of example, but only the upper surface (pattern formationsurface) of the substrate W may be treated in these steps (S2 to S7).

In the first to third exemplary processes, the third rinsing step (S7)may be obviated.

While one embodiment of the present invention has thus been described,the present invention may be embodied in other ways.

For example, as shown in FIG. 20, the multiple embosses 61 may beprovided only on the peripheral portion of the substrate opposingsurface 6 a rather than on the entire substrate opposing surface 6 a. InFIG. 20, a multiplicity of embosses 61 are equidistantly provided on afourth phantom circle 69 defined about the rotation axis A1 on theperipheral portion of the substrate opposing surface 6 a.

As shown in FIG. 21, embosses 161 provided integrally with the hot plate6 may be employed instead of the embosses 61 defined by parts of theballs 66.

In the embodiment described above, the extension units 24 are disposedat the same circumferential positions as the corresponding fixed pins 10with respect to the circumference of the hot plate 6 by way of example,but may be offset from the circumferential positions of thecorresponding fixed pins 10 circumferentially of the hot plate 6. Inthis case, with the substrate W kept in the inclined attitude, the fixedpin 10 (fixed pin 210) closest to the shortest extension unit 224 may bebrought into abutment against the lowest peripheral portion of theinclined substrate W, whereby the substrate W is prevented from slippingdown from the hot plate 6.

In the first to third exemplary processes, the substrate W and the hotplate 6 are shifted together into the inclined attitude in order to movethe IPA liquid film 111 laterally of the substrate W in the organicsolvent removing step (S11). Alternatively, a guide member (a guide pinor a guide ring) having a guide surface may be provided in opposedrelation to the peripheral portion of the substrate and, in the organicsolvent removing step (S11), the guide member may be moved inward of thesubstrate W to bring the levitated IPA liquid film 111 into contact withthe guide surface of the guide member. Since the magnitude of thefrictional force occurring between the upper surface of the substrate Wand the IPA liquid film 111 is generally zero, the levitated IPA liquidfilm ill is guided along the guide surface laterally of the substrate Win the form of liquid mass (without disintegration into a multiplicityof liquid droplets) by the contact between the guide surface of theguide member and the IPA liquid film 111. Thus, the IPA liquid film 111can be completely removed from above the substrate W. Where thisarrangement is employed, both the substrate W and the hot plate 6 can bemaintained in the horizontal attitude in the organic solvent removingstep (S11). In this case, the hot plate attitude shifting unit 90 may beobviated from the substrate treatment apparatus 1.

In the organic solvent removing step (S11), the removal of the organicsolvent may be achieved by opening the nitrogen gas valve 52 to spoutthe nitrogen gas from the nitrogen gas outlet port 51 and spraying thenitrogen gas to the center portion of the upper surface of the substrateW rather than by shifting the substrate W and the hot plate 6 into theinclined attitude. Thus, a smaller-diameter dry region is formed in acenter portion of the levitated IPA liquid film 111. The magnitude ofthe frictional force occurring between the upper surface of thesubstrate W and the IPA liquid film 111 is generally zero. Therefore,the dry region is expanded, as the nitrogen gas is continuously spoutedfrom the nitrogen gas outlet port 51. The dry region spreads over theentire upper surface of the substrate W, whereby the levitated IPAliquid film 111 is guided laterally of the substrate W in the form ofliquid mass (without disintegration into a multiplicity of liquiddroplets). Thus, the IPA liquid film 111 can be completely removed fromabove the substrate W.

In the organic solvent removing step (S11), the guide member may bemoved inward of the substrate W and, at the same time, the nitrogen gasmay be sprayed to the center portion of the upper surface of thesubstrate W.

In the embodiment described above, the hotplate 6 is moved up and downto transfer the substrate W between the hot plate 6 and the substrateholding and rotating unit 5 by way of example, but the hot plate 6 andthe substrate W may be transferred by moving up and down the substrateholding and rotating unit 5 or by moving up and down both the hot plate6 and the substrate holding and rotating unit 5.

A slippage preventing member may be provided separately from the fixedpin 210. In this case, the slippage preventing member is brought intoengagement with the lowest peripheral portion of the inclined substrateW for prevention of the slippage of the substrate W from the hot plate6.

Where the inclination angle is sufficiently small or the magnitude ofthe frictional force occurring between the embosses 61 and the lowersurface of the substrate W is sufficiently great when the substrate Wand the hot plate 6 are kept in the inclined attitude, the substrate Wis not moved along the substrate opposing surface 6 a. In this case,therefore, there is no need to provide the fixed pin 210 or otherslippage preventing member for the prevention of the slippage of thesubstrate W. Where components each having a higher contact frictionalforce are provided at distal ends of the embosses 61 (161), for example,the slippage of the inclined substrate W can be prevented only by theembosses 61 (161) without supporting the peripheral portion of thesubstrate W by the fixed pin 210 or the like.

In the embodiment described above, the substrate W is placed on the hotplate 6 and, in this state, heated in the substrate temperatureincreasing step (S10) by way of example. Alternatively, the hot plate 6may be located adjacent to the lower surface of the substrate W held bythe substrate holding and rotating unit 5 to heat the substrate W in thesubstrate temperature increasing step (S10). In this case, the amount ofthe heat to be applied to the substrate W can be controlled by changingthe distance between the hot plate 6 and the substrate W.

In the embodiment described above, the heating temperature of thesubstrate W is controlled by moving up and down the hot plate 6 with theuse of the plate lift unit 16. Where the amount of the heat to begenerated by the hot plate 6 can be controlled at two stages (anON-state and an OFF-state), the heating temperature of the substrate Wmay be controlled without the use of the plate lift unit 16.

In this case, it is possible to rotate the substrate W in the substratetemperature increasing step (S10). In the substrate temperatureincreasing step (S10), the substrate W may be rotated during a certainperiod or the entire period of the substrate temperature increasing step(S10). In this case, however, the rotation speed of the substrate W isdesirably a lower speed (e.g., about 10 rpm to about 100 rpm) such thatthe peripheral portion of the upper surface of the substrate W isprevented from being cooled. Where the rotation speed of the substrate Wis lower, only a small centrifugal force acts on the IPA liquid film 111in the substrate temperature increasing step (S10), thereby morereliably preventing the IPA liquid film 111 from being slit as indicatedby 113.

In the embodiment described above, hydrofluoric acid and APM are used asthe first and second chemical liquids, respectively, by way of example,but a liquid containing at least one of sulfuric acid, acetic acid,nitric acid, hydrochloric acid, hydrofluoric acid, ammonia water,hydrogen peroxide water, organic acids (e.g., citric acid, oxalic acidand the like), organic alkalis (e.g., TMAH: tetramethylammoniumhydroxide and the like), a surfactant and an anti-corrosion agent may beused as the first or second chemical liquid in the cleaning treatmentand the etching treatment.

The substrate W may be treated with only one chemical liquid rather thanwith the plural types of chemical liquids (two chemical liquids).

IPA is used as the organic solvent having a lower surface tension thanthe rinse liquid by way of example. Other examples of the organicsolvent include methanol, ethanol, acetone and HFE (hydrofluoroether).

In the embodiment described above, the chemical liquid treatment(etching treatment, cleaning treatment or the like) is performed at anatmospheric pressure, but the pressure of the treatment environment isnot limited to the atmospheric pressure. For example, the atmosphere ofthe sealed space defined by the lid member 39 and the lower cup portion37 may be controlled at an increased or reduced pressure by means of apredetermine pressure controlling unit. Thus, the etching treatment, thecleaning treatment or the like according to the embodiment describedabove may be performed in a higher pressure environment or a lowerpressure environment which is controlled at a pressure higher or lowerthan the atmospheric pressure.

In the embodiments described above, the substrate W is heated with thesubstrate opposing surface 6 a of the hot plate 6 kept in contact withthe back surface of the substrate W. The substrate W may be heated bylocating the substrate W adjacent to the substrate opposing surface 6 arather than by bringing the substrate W into contact with the substrateopposing surface 6 a according to the present invention.

While the present invention has been described in detail by way of theembodiments thereof, it should be understood that these embodiments aremerely illustrative of the technical principles of the present inventionbut not limitative of the invention. The spirit and scope of the presentinvention are to be limited only by the appended claims.

This application corresponds to Japanese Patent Application No.2014-62400 filed in the Japan Patent Office on Mar. 25, 2014, thedisclosure of which is incorporated herein by reference in its entirety.

What is claimed is:
 1. A substrate treatment method comprising: anorganic solvent replacing step of supplying, to an upper surface of ahorizontally held substrate, an organic solvent having a lower surfacetension than a rinse liquid adhering to the upper surface of thesubstrate, whereby a liquid film of the organic solvent is formed on thesubstrate as covering the upper surface of the substrate to replace therinse liquid with the organic solvent; a substrate temperatureincreasing step of allowing a temperature of the upper surface of thesubstrate to reach a predetermined first temperature level higher than aboiling point of the organic solvent after the formation of the organicsolvent liquid film, whereby a vapor film of the organic solvent isformed below the entire organic solvent liquid film between the organicsolvent liquid film and the upper surface of the substrate, to levitatethe organic solvent liquid film without disintegration, as a liquidmass, above the organic solvent vapor film; and an organic solventremoving step of removing the undisintegrated levitated organic solventliquid film from above the upper surface of the substrate; wherein theorganic solvent removing step includes a first step of removing theundisintegrated levitated organic solvent liquid film in the form ofsaid liquid mass from above the upper surface of the substrate; andwherein the first step includes a step of contacting a guide surface ofa guide member to a peripheral portion of the undisintegrated levitatedorganic solvent liquid film so that the organic solvent liquid film isguided to move laterally off the substrate.